XP Boot Problem & Possible Recovery Options

I've had this installation of XP for over 4 years, and it's a multiuse machine (graphic design, game play, internet terminal, etc). I've installed the core Opsys on C:, and installed all applications on G:. Both drives exist on the same physical harddrive, but C:'s partition is large enough for XP to operate comfortably, but not meant for much file storage, etc. All applications and storage happen on G: or external media.

Inevitably, I eventually needed to use a Restore Point to recover from a bad install, or some other flaky behavior. These usually work just fine, but about 3 years into this installation, I started seeing the boot sequence for XP hang for no apparent reason. It always hangs in the same place every time, and usually I can go back far enough in System Restore and find a point that lets me boot through to the OS clean.

Well, I eventually (inevitably) contracted a nasty piece of spyware, and had to flush out my System Restores to ensure I didn't re-infect myself. Now I'm having the boot hang issue again, and have no restore points to work from in order to resolve this.

I can get into safe mode without a problem, but I couldn't figure out a solution, so, I eventually decided to do an OS Repair with an install CD. This, of course, reinstalled my core opsys files without blanking the registry.

This actually did not solve the problem. The OS hang still happens, even after the repair.

I don't care about this install of windows, but I have a lot of software installed, and all of the apps reside on G:, so are still fully present. I'd wipe the install and start over, but I don't want to have to track down and reinstall all those apps.

Can someone either help me to fix the hang, or help me to somehow back up the portion of the registry that is responsible for all installed applications, and provide instructions as to how to restore those post-reinstall?