David,
I tried both GUI manual update, and try to download with download manager the stand alone installer/setup file after failed with GUI. I tried using Orbit Downloader, some browsers' default download manager (including Opera, Forefox and Chrome), the last I am trying DownloadThemAll (Firefox extension), but all the setup file download stopped at 99%.
I am using dial-up connection with average download speed about 10-15 kbps, so it took about an hour to download avast setup file (theoretically). The download process started normally, I download a lot of files and updates for my other softwares without problem. But after reaching the last percent, the speed drop to zero, I don't know what happening, I don't thing my connection go down, since I can browse website or download other file - just as fine as how it should be - like opening this forum page.
Orbit Downloader, shows the cycle of trying to create new download link and closed download link endlessly (seems just like that), and DonwloadThemAll don't show anything but a zero download speed. And if I tried to pause and resume again, the same pattern started again and again for the last percent. I have been trying those methods again few times a day to see (and pray) if one of them would work - but still no luck.
Since everyone seems doesn't have any problem with the update, so I thought the problem lies within my system/computer, but I just can't guess where it is. I'll try to download on other computer, or try to find another ISP, and see if I can download the setup.
Thanks for the help anyway