I upgraded my dad's XPS 9500 with 32 GB of RAM (I used 2666 MHz because 2933 MHz in our area was a very significant price jump for some reason, I'm pretty sure it was G.Skill Ripjaws), and added a 2 TB NVMe SSD to the second slot (Crucial P1 or P2).

Now, I did this practically immediately when the laptop came in, which means that we have no clue if the issues were caused by the upgrades or not (though the most frequent BSoD stop code indicates that we should revert to an earlier hardware configuration, so those crashes are pretty much certainly due to the upgrades).

The stop codes (that my dad managed to photograph to show me) are as follows:

BAD_POOL_CALLER (most frequent)

SYSTEM_SERVICE_EXCEPTION

DRIVER_IRQL_NOT_LESS_OR_EQUAL (What failed: mfefirek.sys)

There were apparently some other stop codes that my dad didn't photograph in time.

I used system diagnostics to run the most extensive tests it could on the RAM and storage, and it found no errors after several hours.

Now, I would just put the original RAM back in, but the problem is that the kit is back at home and we are on vacation. These BSoDs are happening every few hours and since my dad does a lot of work on his computer, he finds these crashes really annoying (thankfully he has a habit of constantly saving his work so he hasn't lost much work due to them).

If you have any ideas for how I can potentially solve this problem, I would appreciate your help greatly.