Hi there,
Forgive me if I'm teaching you to suck eggs, but not sure what your level of knowledge might be or what you've already tried.
I use XP, so some may not work on 7, but it's worth a try.
I'd look at all of these before deciding which might suit your situation best.
I always disconnect from the internet and disable the antivirus.
Antivirus is very useful, but often plays hell with processing.
I stick a reminder over the antivirus icon to make sure I restart it before going back online! Maybe 'noddy' but works for me!
You could try one (or all) of the following ;-)
Hit, Control Alt Del to bring up Task manager and select Processes (I think you've probably done that).
Write down the Image names including the .exe and search with Google to see if they are system critical.
Try a 'clean boot' with minimal services
http://support.microsoft.com/kb/331796 Download Tweaknow Regcleaner
Use Startup Manager from Tweaknow to eliminate all of the stuff from startup that isn't necessary.
http://www.tweaknow.com//index.php I'm fairly sure there is a way to create a dual boot to 'normal' and 'clean boot' which creates a choice on the dos screen before starting up. Can't remember exactly how it's done right now but I'll have a think, but that might be XP.
I know 7 has a dual boot option for different os's like 7 and XP. I'm not sure if it allows two 7 options with different startup configurations.
Or... try this for windows 7. It details use of msconfig and autoruns from Microsoft for startup problems.
http://www.sevenforums.com/software/111180-program-runs-startup.html Hope one of these helps!
Steve