Basic specs: Windows 7 Home Premium SP1, Samsung 840 Evo 250GB SSD (OS), Seagate Barracuda 1TB HDD (some games/media), Z87-PRO motherboard, i5-4690K at 4.0GHz, GTX 960, 16GB RAM (2x8GB), Xonar DGX sound card.

It's been happening for awhile now, and I have no idea what's causing it - I'm going about my business (sometimes just after a restart, sometimes when the computer's been running for awhile), the computer spazzes out - the system clock keeps ticking and things visually still run okay, but I can no longer open or close windows including Task Mananger, and the computer can't be properly shut down. While it's acting wonky, the disk access light constantly blinks at intervals of about a second - when I managed to get it to enter shutdown once (took an hour to finally finish), the blinking continued for the entire duration.

I can't stay here for diagnosis (crazy late), but I'll be back in a couple hours. Hopefully one of you guys have at least a vague clue of what's going on.