I also got it resolved a little differently.
I read on a couple of different Adobe threads that some of the GPU plugins were the problem. Apart from the folders, I deleted all the plugins in the en_US folder, then started Premiere Pro. It finally booted up and I was able to activate. then I restored all the plugins, apart from the three GPU plugins, and started again. This time it opened Premiere fine, but the program froze as soon as it started.
I then switched to XP SP2 Compatible mode. Works like a charm.
Glad i got it to work. Was getting a little frustrated.