I built a new system with Windows 8 and was having random freezing issues. I tried updating drivers and the BIOS for my motherboard to no avail.
Oddly enough it seemed to get better when the Intel virtualization extensions were disabled but still not gone completely.
After a bit of digging I found a suggestion to disable dynamic ticks which is a new powers saving feature in Windows 8.
Simply open an elevated command prompt, issue the following command, and reboot:
bcdedit /set disabledynamictick yes