Blue screen! Tested components!

[samcuddy123]

Hi guys!
So I've been having a few problems with blue screens, started a while back but only the one so I backed up my data and just let it lie, they became more frequent, so I had a brand new hard drive lying around im using for another build so I threw that in (took the old hard drive out) but still had the same problems, I've also had memtest running for a good 18 hours, 6 passes later no errors, no high temperatures, I'm baffled into what else it could be, any input would be great ?
Thanks
Sam

 

[ComputerBorks]

The only thing I can think of is reinstalling Windows.

 

[samcuddy123]

Sorry I missed that part out, I have installed a completed fresh copy of windows, same problem sometimes blue screen after a couple of hours sometimes blue screen within minutes, completely random