Windows XP Pro - cannot login?

Hello,

I have a Windows XP Pro Dell PC. The PC starts and at the welcome/logon screen when I click on a user it stays there doing nothing. I started with system repair, recovery, ..... and finally formatted the hard drive and re-installed Windows XP Pro using the Dell "Reinstallation CD". I am still having the same issue. After the re-installation i also tried going into the safeboot and still cannot logon.

Hoping that somebody and help me. Thanks.