[Yet Another] Can not install Avast Internet Security 6

I’m using Windows XP SP3 32bit and Bitdefender IS 2010.
After reading lots about AIS and using AIS 5 in virtual machine for a month, I decided to switch from Bitdefender to Avast:

I uninstalled Bitdefender > restarted > used Bit’s remove tool > restarted > ran AIS 6 setup file, but then nothing appeared.
I ran it again and found out that the setup file only extracted files to system’s temp folder and started avast.setup process. The problem is that this process did nothing (CPU: 0%, Mem Usage: 92K, VM Size: 144K, Handles: 2, Threads: 1; those number didn’t change for more than 10 minutes, then I manually ended the process).
After searching for solutions in this forum, I’ve tried these: restart and try install again, redownload the setup file (which checksum is identical to the old file), run AIS 5 setup file (I had hoped it would install normally as in the virtual machine, then I could update it to version 6); before each try I deleted all temp files (just to make sure) but the same thing happened everytime.

Now I’m using Bitdefender again and typing this post. Could anyone help me to find the problem and fix it?

PS: Honestly, I didn’t think I would encounter this much trouble so I was pretty surprised. I originally wanted to upgrade to Bitdefender 2011 but it has lots of BSOD errors, so I checked other security softwares. I chose Avast because it works well and fast in my virtual machine and it suits me best(after trying Avira, GDATA, Kaspersky and Norton). I hope this will not be my first and last time (or try?) using Avast in my daily works.

Thank you very much for your help.

Did you have any other antivirus in this computer besides BitDefender? Was it fully uninstalled too?
I suggest an installation from scratch:

  1. Download the latest version of avast! Uninstall Utility and save it.
  2. Download the latest avast! version and save it.
  3. Uninstall avast from Control Panel (if possible). If, for any reason, you can’t run it, try booting in Safe Mode and doing it from there. Anyway, boot after that.
  4. Run the avast! Uninstall Utility saved on 1. If, for any reason, you can’t run it, try booting in Safe Mode and doing it from there. Anyway, boot after you’ve run it.
  5. Install avast! using the setup saved on 2. Boot.
  6. Register your free copy or add the license key for Pro.
  7. Check and post the results. If, for any reason, you did not solve, try doing the step 3 in Safe Mode anyway.

I’ve tried running avast uninstall utility (although I have never installed avast so I don’t know what version I should choose to uninstall so I chose v4). I know avast wasn’t installed because I used a program to snapshot the system drive before and after running avast setup file then compared those snapshots, only temp folder had new files and no registry key was added/modified.

I would do a search for Bit Defender from Windows explorer Start > Search “Even after you use the Bit Defender Uninstall tool”…And delete any folders you find…Then go to Start > Run > Regedit > Edit > Find > and write in Bit Defender…After the search is done Delete whatever is “highlighted only” on the right of your screen…Than click find next and do this until all registry issues of Bit Defender are gone and your registry editor doesn’t find any more…
I used the Norton uninstall utillity tool and I still found reminants of Norton left behind…Also I used the Avast 4.8 Uninstall tool nand couldn’t put in Avast 5…So I did a search this way and found lots of registry issues and deleted them and than it installed correctly…If you don’t feel comfortable working with the registry … don’t do it or save the registry issues to desktop that you are not sure of…Also search for any Firewall that might have been on your comp before…Luck and welcome to the Forum and Avast

Sadly, after deleting all history registry key (there is no Bitdefender’s files/folders left), I still can’t install AIS 6.

Are you using or were you using any other Security Software with Bit Defender? and " deleting all history Registry Key" Did you search for this Manually?? Like above?

I use Bitdefender, WinPatrol, Sandboxie and TuneUp Utilities 2011.
Yes, I searched manually for Bitdefender using Registry Workshop, the found keys were mostly MRU lists.

Does the Bit Defender have a Firewall with it and if it does it might have changed your machine settings…After uninstalling Bit Defender I would run a Disc Volume Check for errors Right click on drive C…Also your firewall settings… I am guessing you’re using the windows Firewall after Bit Defender has been uninstalled…But do a disc check and fix the errors on next reboot…Let me know how that goes…

I ran a check disk for C drive, disabled windows firewall but I still can’t install AIS.