Unable to login to my HP laptop running XP sp2

I was working on my HP laptop running XP sp2 connected with internet.
I found a considerable perfromance degrade and try to shutdown it but to no success. Then I shutteddown it using power button. Now when I tried restarting my laptop first it takes hell lot of time to display the login screen. And when I tried to login with correct password it shows error message “Domain DOMAIN_NAME does not exist”.

I have restarted it several times but to no success so far.

Is it any kind of virus that hits my system or a system defect?

Please help me.