Kernel Security Check Failure

Could someone please shine a bit of light on this for me please, it's driving me mad. I upgraded from 7 to 10 see if it would fix it but it didn't help at all. Also getting an "APC_Index_mismatch" BSOD aswell but it's not as regular. Any help greatly appreciated.

I would try a CLEAN/FRESH install of W10 instead of upgrading. My googling brought me to this being some sort of driver issue/incompatibility. If that is an issue, the 'upgrade' to W10 probably didn't take care of it. I would do a fresh install (wipe out drive, install from scratch) and see if that helps it.

I'd go with a fresh install as well, I've a feeling that your issues are caused by a bad Windows install/update.

And thoroughly wipe the drive!