Just another suggestion here....
I use a small, free program called Process Explorer that
you can find here:
http://technet.microsoft.com/en-us/sysinternals/bb896653.aspxThe program is free. Use this to find out what service/process is running.
By right clicking on the process and choosing priorities, you will be given the location
that the service/process is running from, along with other info.
You will also be able to suspend or "kill" the process.
Once the process has been stopped, use Revo as suggested above, but this time use the
start up menue option inside of Revo. Find the service/process that is in the start up menu and remove it.
Then try a restart on your system.
If all of the above steps worked as described, the service/process should now be off.
You then can find the location of the remaining file. Do not delete it, but simply rename it first.
Example: Rename Kasperskypain to Kaspersypain1 or whatever.
If the file will not rename, and says "File in use by another process...", then you will need to go back to
Process Explorer and continue the search. If the file does allow a name change, reboot your system 1 more time.
If all comes up well`, check Avast to see if it is now running smoothly. You may or may not need to to a re-install of Avast, depending on the interference.
Do not delete the file you renamed. Run your system for a week or two, just to make sure no other errors pop up.
These are the steps I use to remove stubborn left-overs and it seems to work for me.
From now on, as suggested above, Use Revo for all uninstalls.
Added: In revo, click on tools, then autorun. A list will pop up, simply uncheck the appropriate box.