All programs uninstall with no effect

[gurgle]

Hello,
I recently encountered a problem on my computer: Uninstalling a program has no effect anymore - it's still there.

I click on "Uninstall", the uninstaller runs and comes up with a success message, quits out as it's supposed to... and the program is still there in full! This problem happens with all programs on my computer.

This problem happened about the same time as I installed Revo Uninstaller, which I think is probably causing the issue. However, I can't uninstall Revo Uninstaller... not via Programs and Features, and not via itself.

Also, my avast! antivirus has started to malfunction - it refuses to scan. I doubt these two problems are related, but I don't know.

Please help me  - My hard drives are very close to full now and I have to uninstall some stuff.

[gurgle]

Also:
-I'm using Windows Vista Business 32bit, not SP1
-There is no error message, only a uninstall success message which is false.

[kpac]

Try Revo.

[gurgle]

Read my post, kpac.
Read it.

[kpac]

My bad - sorry about that.

How much free space have you?

[gurgle]

I have 5 GB on my C drive, 9.2 GB on my D drive. All my programs are installed on C drive.