Okay, hopefuy someone can help me because nobody i have talked to so far has. I juts recently bought an 3.6GHz Intel Pentium 4, and a MSI 915P/G. I am building a computer for the first time. I put the processor and motherboard in a new case with a new power supply(480watt), but am using the old RAM, Hard drive(Maxtor 120Gb 7200rpm), and optical drives. We formatted the drive on another computer and installed WinXP Pro. The problem is however, the computer won't boot. I can get into BIOS just fine, everything is recognized and working properly, but when it comes time to start up windows, i get a black screen saying "error loading operating system." I tried using MS-DOS and it searches for a file named "bananna" but can't find it. Then it comes to a message that says device driver not found CD-ROM. I have no clue what is going on at all. I was thinking maybe my CD-RW does not have drivers installed and is not compatible with the motherboard. Still not sure about that. I have also tried booting direct from the operating system disk. Everything works fine, it shows all the files and drivers loading, and then it says at the bottom of the blue screen Windows is Loading. Well, right after this screen, a blue screen comes up saying that windows had a fatal error and shutdown to protect the computer. Then it says to check the hard drive for corruption etc. I know for a fact that my hard drive is good though because it ran the operating system just fine on another computer. So, I know this is a long one, but I am really desperate now, so please someone, help me. I need this computer to work. I dumped too much money into this thing for it to just sit there and look pretty.

Welcome to the PC Guide Forums!! :D

Well, off-hand I'd say that you need to reinstall Windows. You can't just swap hard drives with someone because that specific installation now has drivers installed for the other computer's hardware. Unless the other computer has an identical mobo (or possibly one from the same series as yours) that installation of Windows is going to be flaky at best. At worst, well... this is what can happen.

I'm not sure exactly how far you installed it on the other computer, but if you went through the whole shebang, including registration, then you'll have to wipe it and start over.

Welcome aboard!
Saphalline is spot on here - windoze gets tied to your machine when it is installed. It expects to see certain hardware and if it doesn't it simply doesn't know how to function.
One thing here - when you installed the OS whilst it was on a different PC, did you activate it? If the copy of XP has been activated on one PC, it can't be used on another without contacting Micro$oft directly and explaining the situation; they should 'deactivate ' it and allow you to reactivate on your new PC if everything is OK.