Hio all, I am completely lost as to what could be the issue with this new build, This is my 3rd build and my other 2 went very well and had a few minor issues which i fixed. Anyway, first of all, system specs: CPU: Intel Core 2 Duo E8400 3.0ghz RAM: 2gb G.Skill DDR2 800mhz (2x 1gb kit) Motherboard: Asus P5Q SE/R Video Card: Albatron GeForce 9600GT HDD: 1x Western Digital 1TB PSU: Corsair VX550 watt Sound: On board 5.1ch surround sound and digital out. OS: Windows XP Professional SP2 What the issue is: After computer boots, and logs into windows I load the HTPC front end (XMBC) all goes well for about 1-3minutes and the computer just "hangs" for lack of a better term. The keyboard/mouse does not work, if I am playing music the sound gets repeated over and over again (as a kind of stuttering repeat of the last 1-2seconds of playing) and all network activity stops as well. What I have done: First of all i thought it might have been an issue with the front LCD panel that was on my case (Antec fusion max htpc case) so i completely disconnected it and started again, it still hung. so i re-installed windows, and i still had that issue. Still completely at a loss, i decided to check to see if it was just a windows issue, so i installed Mythbuntu (A linux based HTPC frontend), which worked fine the very first boot, but subsequent ones still hung 1-3 minutes in. With that, i re-installed windows as a last ditch kind of effort to check what is wrong (i can diagnose better under windows than linux ). but this brand new, clean installation still hung as well. At this point I started taking out all hardware components that weren't necessary (CD drive and front LCD Display). I also tried a known working graphics card (an old Nvidia 6200 i had floating around) and it still hung under those conditions as well. I then went and got the Ultimate Boot CD and ran memtest on the RAM, which reported no errors. I also ran CHKDSK on the hard drive, which fixed all the errors, and it still wants to hang. I then swapped Power supplies around to a known working one and it still hung as well. As a very much last ditch attempt to check what is wrong, i pulled all components out of the case, and re-assembled them on my desk to check if undue stress is causing this issue, which it did not fix. I then booted into Safemode in windows, and ran a program called CPU Burn in (a load test) to check CPU, this worked fine under 1hr of load so i booted normally into windows and ran it again for one hour, which it also passed. Other Things that may be helpful: - Video card drivers are up-to-date from Nvidia's website - System temps are fine all running well below 55 degrees so it is not a heat issue - I swapped RAM with another module (although all i managed to do was diagnose the fact that the other module was faulty ) - Nothing shows in event viewer - All components have never been overclocked - All components are 3-4 weeks old Things i still need to do: - Check PSU Voltage on rails - Video Stress test (Can anyone recommend a good one for me to use?) - Check sound card/download latest drivers My Conclusions: I thought that it might be a faulty motherboard, but the fact that it works fine in the BIOS and off the Ultimate boot CD kind of negates that in my opinion. The fact that a known working power supply still had that issue makes me think it is not a power supply issue. The fact that CPU Burn in and Memtest ran fine seems as if it is not faulty ram or faulty CPU, or heat for that matter. With the video card drivers being up-to-date and didnt work under 2 different types of cards, it makes me think the video card is fine. Just lately though, i was doing some more testing under windows.... it does not hang at all under idle, so thats why i ran CPU burn in to take usage all the way to 100% which it still worked under. And thinking more closely i think it might be faulty sound card/drivers (ive still got to get new drivers) as it only hangs now when im running audio or playing music. If it is faulty sound card than that would mean i would have to get a new motherboard wouldnt it? as i do not have another sound card to test it with. As i said, i still need to check sound card drivers to see if it is a sound issue Any help at all would be appreciated. Thanks EDIT: Well... now the computer has hung without playing any sound at all, a possible motherboard issue? sorry if it seems that it is blatently a motherboard issue, i just need some clarification before i go out and get a new one/send this one in under warranty. EDIT2: Now i am really confused, i ran a benchmark in 3dmark 2001 SE to try and stress the video card, which passed through and finished no problem, and to test the audio, i ran the demo for it, which also worked fine, so it seems as if audio is not at fault.