Just tried booting from the usb with Memtest86+ on it, using the installation instructions from the post you linked and my PC won't boot it. Says "Missing operating system". This is using the same...

Really sorry, my mistake - I must've misread or downloaded the wrong version. I will run the + version now. See you tomorrow!

Completed the memtest as requested, no errors detected (I ran the test a bit longer to get to 8 passes after this photo was taken, but same outcome):
90663

Hi axe0,

Just a quick update: I'm yet to run the memory test (I have to use the PC for work today), but I will post again with the results when I'm done. I tried disabling all the startup services...

Yesterday my computer started randomly showing the BSOD 0x000000be ATTEMPTED_WRITE_TO_READONLY_MEMORY. At the time I wasn't doing anything on the PC, but I do have programs such as Plex media sever...