Win 7 Ent x64 Intel i7 , 6GB ram , System on SSD... Symptoms: 1. Some process cannot be killed, not even with force restart (both Windows Security restart or the shutdown command). Which is really bad, I cannot restart the PC remotely or heck, not even a safe restart, has to press RESET or hard power off! 2. Windows Explorer will be in loading state infinitely... some file system module in kernel is screwed!? 3. Commit size is fine, only 3.5GB max is used at that moment! 4. Hardly any cpu usage, no suspicious process! * Not hardware problem, memory tests are fine, cpu burn-in tests are fine... * HDD/SSD are still accessible through cmd!! I have encountered this for a few times already. There's no info whatsoever in the event log... Resource monitor seems ok in most section except "Disk", nothing shown, loading... The same PC/hardware had been on Vista Ultimate x64 for a few months, no such problem whatsoever... --- another thing, probably the crappy nvidia driver problem: when power saving, turn off screen, no video signal at all afterward, 2*mon (1 DVI, 1 VGA).