OK, let me try to make this simple cause that's the way I need any replies. My daughter's pc (given to her by her step-brother) is a Compaq 7000US that originally came with Windows ME, but later had Windows XP Pro installed on it. Her hard drive had become so currupted and so many problems and I took her hard drive out and installed it into my pc as a slave drive. My pc is also a Compaq Presario and came installed with Windows XP Home. I formatted her hard drive and used my System Recovery Cds to install Windows XP home on her hard drive. After doing this I disconnected my hard drive and made hers the master in my own pc. Windows XP Home booted up perfectly and I thought I had done a great job knowing nothing about pcs. So I reinstalled her hard drive back into her pc and now when hers tries to boot up it hangs at the screen where you select what mode to start windows. When I choose normal startup a bar goes across the bottom of the screen and then just sits there. If I try any other mode it scrolls a lot of system files and then stops at the end of them. Knowing very little about computers I am surely at a total loss now. What can I do???? And, thnx for any replies using layman's terms!!!