BSOD driver ntoskrnl.exe - only when playing

Yes mate but what is the temp on the CPU doing? Plus have a look at the PSU for voltages you can use this

Using HW Info PSU

Download HW Info and pick the right bit version - HWiNFO, HWiNFO32/64 -Download -(copy and paste thissite into the search bar) If you do not need the running information in thesmaller right hand panel close it. In the left hand window click on the + forthe individual device groupings and they will open out to the variouscomponents.

Go on opening out further until you get to the device itself. click on it andit will highlight. In the right hand window there will be a very detaileddescription of that device as in brand, speeds model number etc etc These arevery detailed and are just what is needed for searching for drivers etc.

See my pic for an example - in this I have shown my power but it is a laptopand a desktop will show more details if you scroll down that listing.
or
PSU - Test DC Output Voltage but only use a digital meter as an analogue one will inject typically 9v to test and into a 5v or 3.3v rail would not be good.

Ok well I cannot help then the PSU maybe ok but it is a well known fact that this device is overlooked far too often and I was just trying to start eliminating things.

Hope you find the answer soon:)