Random BSOD times, errors: 0x0000001a and 0x0000004e

I know that you ran MemTest86+ overnight with 18 total passes without errors (from your original post) ... so searching for any possible driver corruption which may be passing any bad info to the memory.

Enable Driver Verifier to monitor the drivers.

Driver Verifier - Enable and Disable

Run Driver Verifier for 24 hours or the occurrence of the next crash, whichever is earlier.

   Information

Why Driver Verifier:
It puts a stress on the drivers, ans so it makes the unstable drivers crash. Hopefully the driver that crashes is recorded in the memory dump.

How Can we know that DV is enabled:
It will make the system bit of slow, laggy.

   Warning

Before enabling DV, make it sure that you have earlier System restore points made in your computer. You can check it easily by using CCleaner looking at Tools > System Restore.

If there is no points, make a System Restore Point manually before enabling DV.

   Tip

• If you fail to get on the Desktop because of DV, Boot into Advanced Boot Options > Safe mode. Disable DV there. Now boot normally again, and try following the instruction of enabling DV again.
• If you cannot boot in Safe mode too, do a System Restore to a point you made earlier.

Let us know the results, with the subsequent crash dumps, if any.

Bit of strange to me, too.

Anyway, the crash dump loosely blames the video memory.

Code:

BugCheck 1A, {403, fffff680002ca4b0, d08000000ffaf86f, fffff680002b166a}

Probably caused by : dxgmms1.sys ( dxgmms1!VIDMM_PROCESS_HEAP::Free+a2 )

Followup: MachineOwner
---------

Your motherboard supports Intel HD graphics. Can you remove the graphics card and apply the onboard graphics, at least as a test?

No problem ... take the necessary time.