Logon Initialization Error, or something, HELP HELP HELP.

Alright, now, I've only had this Windows Vista for about two weeks, I'd say?
Mmk, and today, I came home and turned on the computer as usual, and then
instead of the screen where it asks me for my password it says 'logon
initialization error, please see the entry log for more details", except from
what I've heard, you can't get to the 'entry log' unless you freakin' can GET
THE COMPUTER ON. This problem is annoying me mucho, and I'd like it fixed,
this is very stressful. I don't know what else to really say about this
problem, but we have the Vista using the XP's internet, so they're sort of
connected, and my mom thought the problem was something that she had done
earlier today, turning on the firewall on the XP (although I checked and it
says the firewall is off). I'm not sure how that bit of info will help, but
hey, just incase. Hopefully I put this in the right place, and I'm sorry if I
didn't.

 

Ok, boot your macine and press F8 after the usual BIOS reporting screens.
That would be before Vista starting to boot.
Choose Safe mode without networking.
Once inside Vista go to Start, Programs, Accessories, System Tools, System
Restore.
Do a restore to a previous known working state, before the problem showed up.
Follow the on-screen indications and reboot.
That should fix it.
Carlos