I recently took apart my HP 533C and decided to put it back together to use as a third computer. I took the floppy drive, cd-rom, and dvd-rom out of it and put it in my other computer. But i have put in an old cd-rom that someone gave me and i have just that and the hard drive hooked up to the stock motherboard. When i go in i try to install windows xp professional off the disk. It reads the disk and then goes through that whole process. But then after it has to reboot and it goes to either a plain blank screen or it goes to a blank black screen that will show, "operating system not found." i have tried several times and i am not sure why exactly this is happening. I have tried moving the cables around to the different IDE slots. I have no clue anymore! Can someone please give me an idea of why is this happening. Thanks in advance for your help!