It seems a hardware problem. First, check your CPU temps. Then, check your RAM (use memtest86+) http://www.memtest.org/ Also your PSU (swap with another if you can) You can also try a CMOS reset Could be many things, so you have to test step by step.
Don't delete anything, .NET 4(.5) on Windows 8 is a different animal. There are no setup files to remove, its already slim
I DON'T really remove any .NET components, only the stuff in SetupCache that is used for displaying the install/uninstall progress in multiple languages and repair