Cannot log on to user or admin says domain unavailable

I am running windows xp. I restarted my computer today when it came back on it was asking for a password(which I had never put one on) and would not let me log on. I tried using safe mode to log into the admin account and the same problem. No password has worked.

I downloaded the program from here http://pogostick.net/~pnh/ntpasswd/ on a friends laptop but cannot get the image to copy to a cd?? Can anyone help me out?

 

ok got the password software running and blanked the passwords out. However it is still saying the domain is not available and I still cannot log on.

 

http://support.microsoft.com/kb/555939

If you have an XP CD (not a restore/recovery but a genuine MS windows disk) you can try a repair.
http://michaelstevenstech.com/XPrepairinstall.htm