I am going to jump into this thread because I have exactly the same problem, and have so far followed the suggestions, and have had no luck with getting the program to update manually or automatically.
The last suggestion by Tech to completely uninstall and do a clean reinstall did NOT solve the problem. Symptoms stay exactly the same.
I had no issues with the reinstallation, it just did not solve the problem...
Anybody else have a suggestion to help solve the problem? This obviously gets to be more and more serious an issue as my running program gets more and more out of date...
If I use the Control Panal Add/Remove, I can update the program, but that does not update the virus definition file.
The following section of the log file might help:
22:29:09 min/gen Started: 23.05.2010, 22:29:09
22:29:09 min/gen Running setup_ais-221 (545)
22:29:09 nrm/sys Operating system: WindowsXP ver 5.1, build 2600, sp 3.0 [Service Pack 3]
22:29:09 nrm/sys Memory: 27% load. Phys:2092596/2097151K free, Page:4194303/4194303K free, Virt:2070704/2097024K free
22:29:09 vrb/sys Computer WinName: NAVSTATION
22:29:09 min/sys Windows Net User: SYSTEM
22:29:09 min/gen Cmdline: /verysilent /noreboot /stopstat "C:\WINDOWS\TEMP\aswUpdSum.ini" /session "5"
22:29:09 vrb/gen Operation set to INST_OP_STOP_STAT
22:29:09 min/gen Old version: 221 (545)
22:29:09 vrb/reg Deleted registry: Software\Alwil Software\Avast\5.0\UpdateReady
22:29:09 dbg/fil filRenameOnReboot:!bSuccess
22:29:09 dbg/fil filRenameOnReboot:!bSuccess
22:29:09 dbg/fil filRenameOnReboot:!bSuccess
22:29:09 nrm/sys Using temp: C:\WINDOWS\TEMP\_asw_aisI.tm~a00884 (66707M free)
22:29:09 min/gen LockInstance failed: 0x2000000A
22:29:09 nrm/pkg Transferred: files 0, bytes 0, time 0 ms
22:29:09 nrm/pkg Retries: total 0, files 0, servers 0
22:29:09 vrb/fil NeedReboot=false
22:29:09 min/gen Return code: 0x2000000A [Another instance of setup is already running. Please wait until it finishes and then try to run it again.]
22:29:09 min/gen Stopped: 23.05.2010, 22:29:09