Download Autoruns and if you still run 32-bit download a rootkit scanner.
Autoruns allows to view the objects that are configured
to start automatically other accounts.
Autoruns is written by Microsoft
and thus shows any locations of things that automatically start.
In Jeff's example, one
something that came back was a suspicious driver entry in Autoruns.
Autoruns is fantastic,
but the suggestion to rely on the Publisher may not be useful.
Once software is unchecked from Autoruns, it will not start and can't prevent you from removing it.
Boot into Safe Mode and start Autoruns if you are able to, then go to step 5.
If your computer cannot start up, Autoruns has a feature where it can be
run from a second PC called"Analyse offline PC".
There are tons of complex things you can manage with Autoruns, but to keep things simple,
I'm only going to show you a few tabs.
If the symptoms do not go away and/or the program replaces itself at startup,
try using a program called Autoruns to find the program, and remove it from there.
He also found an oddly-named DLL file hooking into the Winlogon process,
and demonstrates finding and killing the process threads loading that DLL so that Autoruns can finally remove the entries.
On Windows 7, use Autoruns for Windows, a free tool that you can download from the Microsoft website,
shows you all of the programs and processes that run when you start Windows.