Restoring Files After Reinstalling Windows XP?

I had a virus which made it so that when I log onto to my account, I would automatically log out. I got rid of the virus, but it deleted something on my windows, I reinstalled my windows, but it still won't work. I decided just to get a new hard drive, but I heard that when I reinstalled my windows, my files are deleted. I want to check if they really are deleted because the reinstalled didn't bring back the file that was deleted so maybe the reinstall didn't work. But if my files were deleted, can I get them back? If I take it to geek squad, can they get them back?

Thank you.