Can't install Avast 8 fix

[notsokeennow]

I have XP SP3 and the Avast 8 update has sent the computer into a loop.
I can't access Avast to update it or use any other utilities/controls and for some reason safe mode won't load.
Any ideas how I can get my machine running again.
I'm totally disgusted that the original version 8 was released with such devastating results.

[true indian]

Run the uninstaller for any AV's you used prior to avast from here to remove remanents: http://singularlabs.com/uninstallers/security-software/
1. Download avast! Free Antivirus: http://forum.avast.com/index.php?topic=117113.0
2. Follow instructions: http://www.avast.com/uninstall-utility (Run this tool for all prior installed avast! versions..!!)
3. Reinstall avast! with the downloaded installer from point 1.
4. Reboot

[av4me]

Yet another XP broken  :-(

I've wasted 3 hours this morning trying to get back to any version of avast working.

[notsokeennow]

Hi true indian.

Thanks for the suggestion.
The problem at the moment is that the loop is stopping me from getting access to the desktop, programmes etc.
For some reason the F8 key isn't triggering safe mode.
Do you have any further ideas?