Windows experiencing lockups

[Chumbletone]

I've got a computer I built about a year ago, that has started to hang when I'm using windows, even after clean installs. I'll go to click My Computer, navigate through windows explorer, or open a new tab in a browser, and the window will go unresponsive. I can still move my cursor, and if I've got other programs running I can navigate through them (so if windows explorer freezes and I have chrome open, I can still use chrome). between 3-5 minutes after locking up, the system will snap back to working. Previously the system was popping up with BSODs, but changing the SATA controller mode to IDE seems to have resolved that. I've run memtest overnight with no errors, and I've tried swapping the hard drive with two other models from different manufacturers to no avail. I've also RMA'ed the motherboard, although they may have mailed me back the same one.

System build is as follows:
SAPPHIRE 100351SR Radeon HD 7970
Rosewill N900PCE Wireless Card
Seasonic SS-760XP2 PSU
Intel Core i5-4670K
GIGABYTE GA-Z87MX-D3H LGA
Crucial Ballistix Tactical 8GB 240-Pin DDR3 SDRAM DDR3 1600

Any advice would be appreciated.

 

[ste_wilko]

How long after booting up does this happen? Have you checked your CPU temperatures?

Your processor's case temp is 72.72 C, monitor what it's running at