Have you tried calling tech support? Why pay extra for it and not use it?
To be of any help, we need the specs. Give us the exact model of the components when available.
What have you tried doing? Have you changed anything in BIOS? Have you added any new parts? We can't do anything if you don't tell us anything about the problem or machine.
At this point, it could be the CPU overheating, the RAM gone bad, the PSU failing, the motherboard failing, a corrupt Windows installation, a HDD gone bad, or any number of other problems.