My problem is with a computer i built for someone. It ran fine and for about 8 months. Then one day they contacted me and said it wasnt "working". So i brought it to my house and tried to start it up. it will pass POST and after that it leaves me at a black screen with a blinking underscore. i thought maybe the hard drive was the problem so i used western digital's hd tool for testing the drive. first i ran the quit test and it found an error. then it recomended to to run the full media scan so i did so. after that is said that that it found errors and that they were corrected. I ran the tests a few more times and now shows no errors detected, so i am assuming that the Hd is still in good operating condition. i dont know if i can say the same for the data on it though. After that i proceeded to insert my xp installation cd. this is where things got tricky. every once in a while it will detect the cd and start to read it. it prompts me to press any button to boot from cd, so i do so and then i says "setup is inspecting your computers hardware configuration". After that passes it leaves my with a blank screen and seemingly no activity. I tried that a few times and figured that might be caused by a faulty cd-drive. i replaced the drive with a known good one and got the same thing. After that i went on to test the Memory. I tried 2 different programs and 1 ran 20 passes no problem. then the screen started to distort. I think that was caused by an older video card going out, when i first booted up the pc it would have a distorted screen and then it corrected itself sometimes. i replaced it and havent had that issue. the second test i ran just didnt work flat out( i think it was a bad program).I am currently running Memtest86+ v1.70, due to what ive read in this forum. so far ive had 4 passes and no probs. also anything from a bootable floppy seems to run fine. the bootable cd's is where i seem to be having the problems.I tried a xp pro, xp home, The ultimate boot cd and still hangs. i am wondering if maybe the ide channels that the cd drive and hard drive might be working intermittently.they are on differnt ones. both as master. Or could this be a problem with the cpu the board is an intel d865perl that was packaged with a celeron D processor(i think). I also updated the bios to the latest version. If any one can offer any help or ideas please let me know. i am thinking about pulling out the hd and seeing if it will boot one of my other pc's. is there any way to test the mobo with out swapping out a new one, since i dont have a spare intel board?