I would suggest to reinstall Windows again, and make sure you install the correct and latest drivers for your system (provided by either Windows or preferrably the hardware manufacturer).
If that doesn't solve your problem, I'd suggest to run diagnostics on your hardware.
Most HDD manufacturers provide diagnostic tools for their HDD's on their website, which checks the
SMART status of the HDD.
It might also be useful to run a scan for bad sectors. The program files and swap file may be compromised if it tries to read/write on a bad sector, ultimately causing the system to crash.
If everything is fine with your HDD (well, if you have one, I presume it's not an SSD?) you should check the memory for errors.
Windows 7 provides a memory diagnostic tool which can be found at:
Control Panel -> System and Security -> Administrative Tools -> Windows Memory Diagnostic
If you are still unable to find the problem doing the above, well, let us know and we'll see what we can do.