Each time I try to install a program on my computer (running windows 7 RC), a setup.exe dialog pops up:

> 
> The Windows Installer service is
>  unavailable. Another application may
>  be rerunning setup. Finish any
>  installations in progress, or restart
>  your computer, and then re-run setup.
> 
> 
> 

I did restart a few times, and there's no ongoing installation I can think of.

If I pop up a task manager, I can indeed see a msiexec.exe process. I can kill it, but it will immediately start again. Is there a way to determine which program is installing and to abort it?