I ran a chkdsk command as admin, no problems found.
But.. i downloaded memtest for windows, and literally as soon as it begins it's found an error, i went into the bios and set the memory to X.M.P defaults and tried again, got this from memtest
"Memory error detected! Copying between 10e7849f and 10e7833b did not result in accurate copy. MemTest has detected that your computer cannot accurately store data in RAM" etc..
Well, guess it's time to contact G.skill then