BSOD with Qualcomm WLAN(?) - BCCode d1, 4a

Usually when Driver Verifier finds nothing, which is the case we are facing, and the bugchecks are consistently
faulting on core Windows components it's time to test the hardware.

koolkat77 said:

Test and Diagnose RAM Issues with Memtest86+:

• RAM - Test with Memtest86+

   Tip

• Pay close attention to part 3 of the tutorial "If you have errors"
• Test the RAM with Memtest86+ for at least 7-10 passes. It may take up to 22 passes to find problems. Make sure to run it once after the system has been on for a few hours and is warm, and then also run it again when the system has been off for a few hours and is cold.

Post back with the results :) .

asura8 said:

You had previous stately not to check the SSD drive; the link you had provided for checking the hard drives seemed to indicate a CD requirement, while I don't have any burnable CDs at the moment. Is there a utility for checking a Western Digital hard drive from a USB drive?

I meant not to use the CHKDSK utility on the SSD.
For now let's focus on the RAM as it seems to play a bigger role in the bugchecks.

If you don't want to use a CD to test you can use YUMI – Multiboot USB Creator to create a bootable USB (instructions are found at the bottom of the page).

asura8 said:

Memtest86 is now running merrily along; though I imagine it'll be about an hour and a half before even one pass is done, so full results will not be available until tomorrow.

Yes memtest is an "all-nighter" type of test, that's normal.

asura8 said:

I will note, aside from verifier.exe having a brief blue screen on an attempt to boot, it seemed to be doing pretty dandy. But I'm not even sure it GOT to really crash with verifier.exe working - it literally crashed on boot. Is that relevant?

Driver Verifier is designed to crash as soon as it detects drivers trying to commit "bad moves"
in the kernel which will lead to a crash anyway.
The benefit of a crash initiated by Driver Verifier is that the driver at fault is usually
caught red handed, so yes it should have crashed with DV enabled but nothing was detected
which sometimes happens.
That usually suggests a memory issue.
By the way make sure you read Part 3 of the tutorial if errors are found during the test.

Assuming that the memory is ok, a fresh installation is always a good idea but we want to avoid
making the same mistakes on the newly installed OS.

I would start backing up the data in preparation for a clean install.
Once that is done I suggest you run driver verifier using THIS METHOD and wait for the system
to crash a couple of times it might shed some more light as to what's really going on.

BTW aside from the SSD being in good condition, is the firmware up to date?

asura8 said:

Samsung Magician reports the firmware as up to date of the hard drive.

So - the installation is new enough that there is literally nothing that NEEDS backing up. Just some software like Steam that is easily (and perhaps better) reinstalled. In that case, do I need a full back-up to restore from, or would it suffice to just make a System Restore point prior to using DriverVerifier?

By backup I meant your personal files, which you can't reinstall or download.
A system restore point will suffice.

asura8 said:

And just to check to make sure I understand, we're essentially doing a DriverVerifier test again, except this time with Force Pending I/O Requests set to off, and waiting for a couple of crashes this time rather than the first one.

Correct, but these are the settings that needs to be applied (quoted from the tutorial):

1. Go to Start and type in "verifier" (without the quotes) and press Enter
2. Select "Create custom settings (for code developers)" and click "Next"
3. Select "Select individual settings from a full list" and click "Next"
4. Select everything EXCEPT FOR "Low Resource Simulation", "and "Force Pending I/O Requests" and click "Next"
5. Select "Select driver names from a list" and click "Next"
6. Then select all drivers NOT provided by Microsoft and click "Next"
7. Select "Finish" on the next page.