Disable avast services

Hello,
I installed avast 4 (free) home edition on my laptop. After the installation, the computer will not let me logon. If I log on as administrator or any other user, the computer instantly logs me back off.
Safe mode, safe mode with command prompt, last good known setting etc do not work.

I copied back the original registry files from c:\windows\repair but this did not work.

I have been able to boot with the windows installation cd and go to the recovery console. From there, i deleted the avast files and disabled all the avast services except:
avast! antivirus
avast! web scanner and
avast! mail scanner

what commands do I use to disable the above 3 services whilst in the recovery console?

Unfortunately, you can’t do it through the recovery console…
Which other antivirus did you have running in this computer? How did you uninstall it to install avast?