Thanks ElectronDF - will try some of that.

Apps. I don't have the exact error right now, but it's actually given me several different errors on the blue screen. It's not always the same one.

One of the last ones I wrote down was:
IRQL_NOT_LESS_OR_EQUAL
STOP:
0x0000000A, (0xFFFFFFFFFFFFFFF, 0x000000000000002, 0x000000000000001, 0xFFFFF8000C109C22)