I have been working with my new desktop for months now and I can not seem to sort out the issue of the spontaneous freezing. And yes, I do me spontaneous. Anywhere from 30sec. on start up, to 28hrs. later. I have replaced the Processor, same issue. I have replaced the mobo. and video card as well. Still to no avail. I am running with more than one OS so I know It's not Windows 7 (getting that out of the way ahead of time). I finally gave up and took the custom into a shop where they determined it was an issue with my video card. "Then, why are we reading this?!" Because unfortunately after RMA the video card (new) the issue still exists. The shop replaced the current video card with a similar model (Radeon 5870) and seemed to resolve the problem, yet, whey did a new video card not fix it? Is it a compliance issue? I called ASUS and they have no records of any ATI model video cards not being compliant. The only other information I can give you, is that when the freezing does happen, it happens more frequently until I let the computer sit for a while. Thank you ahead of time, usually I'm not the one to ask for help, so I hope you guys have more luck than I did. Radeon 5850 PCIe 2.0 x16 AMD Phenom II x4 3.4ghz 2x 2GB Mushkin DDR3 500Gb WD HD + (old garbage) Samsung 60Gb HD ASUS Crosshair III Motherboard w/Supreme FX X-FI Soundcard Warlock 900W PSU ASUS (new) BD-ROM / HL-DT-ST CDRW/DVD PS- Yes I used Memtest and Windows memory diagnostic with no problems found.