I have windows 8.1 machine. The problem started with a secondary drive disappearing. Then I started getting DPC_WATCDOG_VIOLATION and the machine would restart but then I'd get a DISK BOOT FAILURE. I'd let the machine sit for a while then restart then it'll boot fine. I ran chkdsk and the tools for detecting HD problems available in windows 8 and no errors detected. Please HELP me point to the culprit!!! Could it be the power supply? Hard dirve?