I am a long time avast! user, and have used it on all of my PCs (Win2K, WinXP and Vista). Last night, my new Acer laptop (running Vista Home Premium), on which I had Avast 4.8 installed since purchase, decided to throw up on me. As I was composing an e-mail, the PC locked up. I did a reboot, and when the laptop rebooted, I received the dreaded 0xc0000005 error, saying "the application failed to initialize." In addition, I received not one, but two Vista dialogs saying that the avast "GUI component" failed to start. As a result, no blue ball in my system tray. I uninstalled avast and reinstalled using my saved setupeng.exe copy - but no use. The first time, I received an error message stating that a service failed to start. So I uninstalled again, and tried to delete the "Alwil" folder in Program Files. Whoops - can't do it, don't have enough permissions. So I rebooted and logged in as administrator, and tried again to delete the folder. Uh oh - even as Administrator I couldn't do it! I downloaded the aswclean.exe file that others have referred to on this forum, and ran it as administrator in safe mode - that appeared to clear it out. So I attempted to install again. No dice. Same 0xc0000005 error, same Vista dialogs about the GUI component. In order to at least use my computer, I had to download and install clamwin.
The PC came with Norton Internet Security 30-day trial, but I immediately uninstalled it prior to installing avast, and the PC ran flawlessly until last night. I recall it had just downloaded a new virus database, but the program itself did not update, so I don't believe that was the culprit. I am running no Norton, McAfee, Zone Alarm, or other problematic programs. My laptop is an Acer Aspire 4520-5458, 1gb RAM, 120gb HDD, nVidia GeForce 7000M graphics, Windows Vista Home Premium, and I use Windows Defender, Spybot S&D, and Windows Firewall (though I may investigate more robust solutions for that).
I have searched the forums for this same problem, and while others have experienced similar issues, no one has experienced this particular problem - program stop while running. I have tried the steps outlined by others to reinstall, to no avail.
All of my Alwil folders have been deleted, so no install logs to look back upon. I could understand why a program might fail to initialize on first start, but not while running. I hope someone has some ideas on how to fix this issue, because I feel much safer with avast than with just about any other AV program.