PC startup problem

[pushpushshove]

I tried to reboot my PC last night and it wouldn't cooperate. When I power up, it gets to the blue screen that says, "Windows is starting up..." and sits for 15-20 minutes. Then it finally goes to the screen where it asks me to select an account. This is where I'm stuck. Clicking on the account names gets me nowhere. It doesn't open a box to enter a password at all. I get the same thing in safe mode.

I'm running Windows XP Home. I have the hard drive from my old PC installed as a slave. Is it possible for me to swap master/slave drives and try to boot up that way or is that a horrible idea?

Any suggestions?