windows xp に無料のアンチウイルスソフト（オンライン版）のインストール方法

[REDACTED]

Windows XP(SP3)で，avast_free_antivirus_setup_online.exe　（サイズ7,481,664B）
を実行したところ，赤×印と共に「セットアッププロセス完了中にエラーがありました」と表示されました．
10月 29, 2018　mujie_1029さんのスレッドに書いてある，「Terminal Services」，「Background Intelligent Transfer Service」を手動で開始にしましたが，
同様のエラーが出ました．
機種：Dell　 Precision T5500
CPU:Xeon W5590 @3.33GHz, 3.43GB RAM

どのように対応したらいいか，御教示頂きたく,お願い申し上げます．

ログ(Errorのみ)は下記のとおりです．（Infoだと，サイズオーバーで送れませんでした．）
－－－
2018-11-19 11:56:03.609ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
2018-11-19 11:56:26.718ErrorCurl[2504,2384]'http://f0862499.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12007, Couldn't connect to server)
2018-11-19 11:56:50.000ErrorWinHttp[2504,2384]'http://l9734355.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.200] was not downloaded (12029, A connection with the server could not be established)
2018-11-19 11:56:55.687ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
2018-11-19 11:56:59.859ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
2018-11-19 11:57:22.796ErrorCurl[2504,2384]'http://x4549738.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12007, Couldn't connect to server)
2018-11-19 11:57:45.828ErrorWinHttp[2504,2384]'http://c9006292.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12029, A connection with the server could not be established)
2018-11-19 11:57:51.500ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
2018-11-19 11:57:55.500ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
2018-11-19 11:58:18.375ErrorCurl[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x/servers.def.vpx' from [23.57.92.89] was not downloaded (12007, Couldn't connect to server)
2018-11-19 11:58:42.796ErrorCurl[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x/servers.def.vpx' from [] was not downloaded (12007, Couldn't connect to server)
2018-11-19 11:58:57.921Errortasks[2504,2912]Exception: CURL failed. CURL error code: 28. Timeout was reached. Connection timed out after 15000 milliseconds
Code: 0x0000001c (28)
－－－

[NON]

こんばんは mitukun さん


最近ネットワーク絡みのご質問が多いですね・・・。

できればある程度Info も混ぜていただけるとありがたい(場合によっては添付ファイルとして添付してください)のですが、まず、ブラウザから、ログにあるいくつかのURLにアクセスできるでしょうか？
また、他にお使いのセキュリティソフトはありますか？

[REDACTED]

Info を添付．
－＞
添付の方法を教えて下さい．末尾に付けます．

ブラウザから、ログにあるいくつかのURLにアクセスできるでしょうか？
－＞
ErrorにあるURLについては，全てアクセスできて，ファイルがドウンロードされました．しかし，「このファイルを開けません」というメッセージが出ます．

他にお使いのセキュリティソフトはありますか？
－＞
Yaraiを使っていたのですが，updateしたら，XP未対応で動かなくなってしまい，これをアンインストールしている状態です．

以上、宜しくお願い申し上げます．
Infoinstup[2504,2384]Command: '"C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\instup.exe" /edition:1 /ga_clientid:58128d14-7622-43ae-b7a1-25ff7bd21041 /guid:63cf6e7a-2b31-4b4d-ba45-765fb0163421 /prod:ais /sfx:lite /sfxstorage:C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896'
Infoinstup[2504,2384]CPU: Intel(R) Xeon(R) CPU           W5590  @ 3.33GHz,4
Infoinstup[2504,2384]OS: Windows XP SP3 x86
Infoinstup[2504,2384]Memory: 44% load. Phys:1993416/3601900K free, Page:3979244/4194303K free, Virt:2030012/2097024K free
Infoinstup[2504,2384]DISKs: C:\ - 4GB free / 40GB total
Infoinstup[2504,2384]DISKs: D:\ - 8GB free / 40GB total
Infoinstup[2504,2384]DISKs: E:\ - 0GB free / 40GB total
Infoinstup[2504,2384]DISKs: F:\ - 23GB free / 25GB total
Infoinstup[2504,2384]DISKs: G:\ - 4GB free / 25GB total
Infoinstup[2504,2384]DISKs: H:\ - 8GB free / 25GB total
Infoinstup[2504,2384]DISKs: I:\ - 7GB free / 84GB total
Infoinstup[2504,2384]DISKs: R:\ - 1399GB free / 1862GB total
Infoinstup[2504,2384]Running module version: instup.exe - '18.8.4084.0'
Infoinstup[2504,2384]Running module version: Instup.dll - '18.8.4084.0'
Infomutex[2504,2384]The ownership of the fallback mutex has been successfully taken.
Warninginstup[2504,2384]SWITCHER: init
Warninginstup[2504,2384]SWITCHER: Windows Vista and older detected!
Warninginstup[2504,2384]SWITCHER: launching FixCommandLineOnAnySwitch
Infoinstcore[2504,2384]SWITCHER: started
Infoinstcore[2504,2384]SWITCHER: finished
Warningsettings[2504,2384]Did not find any values in file 'programData\avast5.ini'
Infoshepsync[2504,2384]Trying server IP address '77.234.42.107'
Warningshepsync[2504,2384]Exception: Unable to retrieve path of the program directory! Code: 0x00000002 (2)
Infoshepsync[2504,2384]Trying server IP address '77.234.44.103'
Warningshepsync[2504,2384]Exception: Unable to retrieve path of the program directory! Code: 0x00000002 (2)
Infoshepsync[2504,2384]Current postpone interval: 3600, next 7200
Infoevent_rout[2504,2384]Registering event handler for burger_client.send_event.7. Description: Module: C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\Instup.dll
Infoevent_rout[2504,2384]Registering event handler for burger_client.flush. Description: Module: C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\Instup.dll
Infoevent_rout[2504,1832]Registering event handler for system.network.connectivity_changed. Description: Module: C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\Instup.dll
Warningsettings[2504,1832]Did not find any values in file 'programData\burger_client.ini'
Infowizard[2504,2384]Running module version: HTMLayout.dll - '3.3.2.1'
Infowizard[2504,2384]Loaded module version: C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\HTMLayout.dll - '3.3.2.1'
Infowizard[2504,2384]Setup gui was successfully started.
Infoinstcore[2504,2384]Sfx setup update has started.
Noticeservers[2504,2384]Load: 'urlpgm' key used as the program repository.
Infoservers[2504,2384]Server definition(s) loaded from 'C:\DOCUME~1\Sugimoto\LOCALS~1\Temp\_av_iup.tm~a02896\servers.def'
ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
WarningAddrInfo[2504,3528]Unable to resolve 'j5017497.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,3848]Unable to resolve 'f0862499.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,2568]Unable to resolve 'c9006292.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)

WarningAddrInfo[2504,500]Unable to resolve 'l9734355.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
InfoAddrInfo[2504,3388]'f0862499.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,3696]'j5017497.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,3380]'c9006292.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,3428]'l9734355.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'f0862499.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,1944]'s-iavs9x.avcdn.net' domain was resolved into [23.57.92.89]
InfoAddrInfo[2504,3388]'f0862499.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,3696]'j5017497.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,3380]'c9006292.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,3428]'l9734355.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'f0862499.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'c9006292.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'c9006292.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'j5017497.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'j5017497.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'l9734355.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'l9734355.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'s-iavs9x.avcdn.net' domain was resolved into [23.57.92.89]
InfoAddrInfo[2504,2304]'s-iavs9x.avcdn.net' domain was resolved into []
InfoAddrInfo[2504,2304]'s-iavs9x.avcdn.net' domain was resolved into []
WarningAddrInfo[2504,3444]Unable to resolve 't1754646.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
InfoAres[2504,2384]'t1754646.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,4084]'t1754646.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'t1754646.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4084]'t1754646.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
Infoservers[2504,2384]'http://f0862499.iavs9x.u.avast.com/iavs9x' with [210.239.30.201] chosen for 'program'
ErrorCurl[2504,2384]'http://f0862499.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12007, Couldn't connect to server)
Warningdldwrap[2504,2384]HttpGet: download type switched to WinHttp IPv4
Infoservers[2504,2384]'http://l9734355.iavs9x.u.avast.com/iavs9x' with [210.239.30.200] chosen for 'program'
ErrorWinHttp[2504,2384]'http://l9734355.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.200] was not downloaded (12029, A connection with the server could not be established)
Warningdldwrap[2504,2384]HttpGet: download type switched to Curl IPv6
Warningservers[2504,2384]There is no suitable url for 'program' with IPv6 and http
Warningdldwrap[2504,2384]HttpGet: download type switched to WinHttp IPv6
ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
InfoAddrInfo[2504,1316]'n4665600.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,2984]'d4125126.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,1324]'j6478362.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,2792]'p5472367.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'n4665600.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,1316]'n4665600.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,2984]'d4125126.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,1324]'j6478362.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,2792]'p5472367.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'n4665600.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'j6478362.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'j6478362.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'d4125126.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'d4125126.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'p5472367.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'p5472367.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
WarningAddrInfo[2504,3888]Unable to resolve 'p5472367.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,4080]Unable to resolve 'd4125126.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,3268]Unable to resolve 'j6478362.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,3284]Unable to resolve 'n4665600.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
Warningservers[2504,2384]There is no suitable url for 'program' with IPv6 and http
Warningdldwrap[2504,2384]HttpGet: download type switched to Curl IPv4
ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
InfoAddrInfo[2504,2876]'t0317481.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,400]'x4549738.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,1608]'j4528339.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,2560]'g7830334.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'x4549738.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,2876]'t0317481.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,400]'x4549738.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,1608]'j4528339.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,2560]'g7830334.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'x4549738.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'t0317481.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'t0317481.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'g7830334.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'g7830334.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'j4528339.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'j4528339.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
WarningAddrInfo[2504,552]Unable to resolve 't0317481.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,1056]Unable to resolve 'g7830334.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,3436]Unable to resolve 'j4528339.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,3332]Unable to resolve 'x4549738.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
Infoservers[2504,2384]'http://x4549738.iavs9x.u.avast.com/iavs9x' with [210.239.30.201] chosen for 'program'
ErrorCurl[2504,2384]'http://x4549738.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12007, Couldn't connect to server)
Warningdldwrap[2504,2384]HttpGet: download type switched to WinHttp IPv4
Infoservers[2504,2384]'http://c9006292.iavs9x.u.avast.com/iavs9x' with [210.239.30.201] chosen for 'program'
ErrorWinHttp[2504,2384]'http://c9006292.iavs9x.u.avast.com/iavs9x/servers.def.vpx' from [210.239.30.201] was not downloaded (12029, A connection with the server could not be established)
Warningdldwrap[2504,2384]HttpGet: download type switched to Curl IPv6
Warningservers[2504,2384]There is no suitable url for 'program' with IPv6 and http
Warningdldwrap[2504,2384]HttpGet: download type switched to WinHttp IPv6
ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
WarningAddrInfo[2504,4184]Unable to resolve 'j6285672.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
InfoAres[2504,2384]'j6285672.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
WarningAddrInfo[2504,4192]Unable to resolve 'm4414883.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
InfoAddrInfo[2504,4200]'s9658017.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4180]'j6285672.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
WarningAddrInfo[2504,4208]Unable to resolve 's9658017.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
InfoAddrInfo[2504,4200]'s9658017.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,4180]'j6285672.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'j6285672.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'s9658017.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4188]'m4414883.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'s9658017.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,4188]'m4414883.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'m4414883.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'m4414883.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
Warningservers[2504,2384]There is no suitable url for 'program' with IPv6 and http
Warningdldwrap[2504,2384]HttpGet: download type switched to Curl IPv4 SSL
ErrorAres[2504,2384]Unable to resolve hosts after 1671 ms (258, The wait operation timed out.)
InfoAres[2504,2384]'k7157301.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4296]'b6648802.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,4312]'p4539956.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAddrInfo[2504,4304]'k7157301.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4296]'b6648802.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4312]'p4539956.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAddrInfo[2504,4304]'k7157301.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'k7157301.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'b6648802.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'b6648802.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
InfoAres[2504,2384]'p4539956.iavs9x.u.avast.com' domain was resolved into [210.239.30.201]
InfoAres[2504,2384]'p4539956.iavs9x.u.avast.com' domain was resolved into [210.239.30.200]
WarningAddrInfo[2504,4300]Unable to resolve 'b6648802.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,4316]Unable to resolve 'p4539956.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
WarningAddrInfo[2504,4308]Unable to resolve 'k7157301.iavs9x.u.avast.com' into IPv6 (11001, No such host is known.)
Infoservers[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x' with [23.57.92.89] chosen for 'program'
ErrorCurl[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x/servers.def.vpx' from [23.57.92.89] was not downloaded (12007, Couldn't connect to server)
Warningdldwrap[2504,2384]HttpGet: download type switched to Curl IPv6 SSL
Infoservers[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x' with [] chosen for 'program'
ErrorCurl[2504,2384]'https://s-iavs9x.avcdn.net/iavs9x/servers.def.vpx' from [] was not downloaded (12007, Couldn't connect to server)
Warningsettings[2504,316]Did not find any values in file 'programData\avast5.ini'
Warningsettings[2504,1832]Did not find any values in file 'C:\Documents and Settings\All Users\Application Data\AVAST Software\Avast\burger_client.ini'
Errortasks[2504,2912]Exception: CURL failed. CURL error code: 28. Timeout was reached. Connection timed out after 15000 milliseconds Code: 0x0000001c (28)

[NON]

Info を添付．
－＞
添付の方法を教えて下さい．末尾に付けます．

とりあえず、今ある分で大丈夫です。
なおファイルを添付するには、記入欄の下の「Attachments and other options」を開くと、添付のためのボタンが出てきます。

ブラウザから、ログにあるいくつかのURLにアクセスできるでしょうか？
－＞
ErrorにあるURLについては，全てアクセスできて，ファイルがドウンロードされました．しかし，「このファイルを開けません」というメッセージが出ます．

中身は暗号化されているので、開けなくても問題ありません。
例えばメモ帳で開いてみれば、意味の分からない文字や漢字の羅列が出てくるはずです。

ログを見る限りでは、DNSによる名前解決はできているものの、それ以後のダウンロードで失敗しているようです。
ブラウザからファイルがダウンロードできるということは、インターネットの経路は正常と考えられますので、なぜかAvast のインストーラーからはアクセスができない状態ということになります。
別な方の事象はDNSの名前解決でコケていたので、また別な事象ですね。


XPだと、古い手ですが、Winsock のリセットも効果があるかもしれません。
下記リンクの、「Download@MajorGeeks」をクリックして、ツールをダウンロードしてください。
（「netsh winsock reset」が使えればそれでも良いです）
https://www.majorgeeks.com/files/details/winsock_xp_fix.html

ダメなようなら、古いバージョンのリンクを送ります。

[REDACTED]

早速のご回答，有り難うございます．
Winsock のリセット：
①netsh winsock reset
－＞
リセットできましたが，状況は変わらずです．なお，ログの行数は少なくなりました．
②「Download@MajorGeeks」をクリックして、ツールをダウンロードし実行
－＞
リセットできましたが，状況は変わらずです．なお，ログの行数は少なくなりました．

ログを添付します．
日本語URLでは，「詳細オプション」をクリックすると，「添付」と言う項目が出て，添付できました．

[REDACTED]

添付ファイル忘れました．

[NON]

やはりダウンロードでコケていますね。
標準URLと予備URLがどちらも失敗しているので、見た目上はファイアウォールでブロックされているような見え方ですが・・・。

インターネットへの接続に、プロキシを経由する必要があるような環境ということは無いでしょうか？

一応、旧バージョンのリンクをお送りしますので、こちらでオフラインインストールできると思います。バージョン17.2か17.3辺りならいけるはずです(逆にそれ以上はダメです)。
ただ、インストールは出来ても、ウイルス定義のアップデートができるかは要確認です。

[REDACTED]

早速のご返事ありがとうございます．

インターネットへの接続に、プロキシを経由する必要があるような環境ということは無いでしょうか？
－＞
プロキシ経由の接続です．

一応、旧バージョンのリンクをお送りしますので、こちらでオフラインインストールできると思います。バージョン17.2か17.3辺りならいけるはずです(逆にそれ以上はダメです)。
ただ、インストールは出来ても、ウイルス定義のアップデートができるかは要確認です。
－＞
やってみます．

[REDACTED]

avast_free_antivirus_setup_offline2314.exe (17.7.3660)
－＞同様に「セットアップ完了中にエラー」で駄目．
（ドウンロードしてプロパティーを見ないと，Versionがわからない．）

avast_free_antivirus_setup_offline2286.exe (17.1.3394)
－＞
「UI failed to load.
This is really embrrassing.
AV service is not responding.」
が表示されるも，エラーは出なかった．
－＞
XPを再起動．

avast起動．
右上「メニュー」－「設定」－「更新」－「プロキシ設定」で，プロキシを手動設定．
さらに，パソコンのIEの「ツール」－「インターネットオプション」－「接続」－「LANの設定」で，プロキシ自動検出から手動設定に変更．

右上「メニュー」－「設定」－「更新」－「プログラム」で更新．
－＞18.8.4084（2018/11/15)に更新された．
右上「メニュー」－「設定」－「更新」－「ウイルス定義」
－＞181122-0（2018/11/22)に更新された．

お陰様でインストールできました．
反省：プロキシ自動検出でなく，手動設定にしていれば，オンラインでインストールできたかも知れません．

丁寧な説明，有り難うございました．

[NON]

無事インストールできたとのことで良かったです。

（ドウンロードしてプロパティーを見ないと，Versionがわからない．）

そうでした、すみません。

プロキシ経由の場合、Avast のダウンロードもプロキシを経由する必要があるため、Avast 側で設定を認識できない場合、インストールできないことになります。