WindowsXP freezes up when changing Appearence!

[Salmerin]

I am having a problem with my windows XP SP2, just recently I have noticed that my PC doesn't boot-up properly, I get no error message, no blue screen of death, nothing that tells me that something was wrong with the boot-up. The only thing that happens is that when it is loading up, and just before it goes into windows it shuts down completely. I have to let it sit there doing nothing for about a minute or two and it will then boot-up properly. The other thing that happens is that when I tried to change the Appearence on WinXP it freezes up and when I hit the re-boot button it does what was explained above. The HD is kinda new so I don't think that is the prob, there's no spyware or viruses cuz I have checked it three times in one day and there's no spyware detected nor viruses, so I am stuck with this problem.
I have exhausted all the knowledge I have on computers and this prob is killing me.

Thanks!

[codered6651]

If you're familiar with the Recovery Console you could do a repair.

In the Windows Recovery Console you can:

Use, copy, rename or replace operating system files and folders, Enable or disable services or devices from starting when you next start your computer, Repair the file system boot sector or the Master Boot Record (MBR), Create and format partitions on drives.

Note that only an administrator can obtain access to the Windows Recovery Console so that unauthorized users cannot use any NTFS volume.