I recently did memtest on my PC that i'm having problems with. If i understand correctly, if i boot memtest USB with UEFI it will not move to other parts of the RAM to test the part it was occupying before?
Here is the information i found on their official support page.
MemTest86 is also inherently limited by the UEFI environment and as such, gives rise to the following limitations:
MemTest86 USB flash drives cannot be read in Windows XP (32-bit) due to its lack of support of GPTdisks
MemTest86 cannot remap itself to different portions of memory in order to run tests in the section of memory it was occupying.