Don't worry about the connectcomputer stuff, realised it's really only used for small business server stuff... some fancy wizard that generates systems id's or something... Not what you need in your situation.

Check for some 'admin' password resets, there were a few going around for XP, Vista should have something similar.

Sorry I can't help with your first (major) problem of this thread. The only thing I can think of is to do a safe boot, then step through the start-up code. you should be able to bypass the networking stuff. Then once in, uninstall or re-install your m/b drivers/chipset/lan stuff... else you should still be able to use the minePE cd and back everything up to USB Disk.

good luck.