login problem

[Jason]

I use XP Por.(stand alone). Sometimes XP won't let me
login to my computer even I used Administrator login name
and password.
But, if I reboot the computer several time, and then it
let me login. What kind of the problem I got, and how do I
fix it?

 

[Ph0eniX]

Review the event logs. Make sure that the Caps Lock is not on when you're
trying to log in. Sounds like the SAM database is corrupt - could be due to
a HDD problem.