Memtest86 Hanging early in process on two identical computers

[KD KD]

I have 2 Dell Optiplex 990 computers. I tried to run the Microsoft memory checker and it seems to hang. So I created USB drive with Memtest86 UEFI.
I have tried the memtest86 on both computers and they both start the test and then seem to fail almost at the start of the test.

I dont know anything about how to use the software but I just leave it alone and let it do its thing. Basically it starts and then seems to hang at Pass 0% Test 18% or on another computer I think it was 80% CPU 0 and the State: \ and this does not move. I have left it for 30 or more. No movement.
I have read that some Motherboards are not compatible but I cannot see mine.
Is there a no fault way to configure the program or what would you suggest.
Thanks.

[David (PassMark)]

Try switching to single threaded mode (1 CPU core) in the Memtest86 configuration screen.

[KD KD]

Thank you for your response. It seems to say the following in the configuration.

Warning your uefi firmware has limited multi processor support

It then seem to say" *Single cpu #0 " When I try to change 0 to 1 it says something about not supporting it.

Does this mean I cant run this program on these dell computers?

[David (PassMark)]

Maybe it was already running with one thread / core. (You can tell this from the main window while the test is running).

If that is the case there is either a serious UEFI BIOS bug or there is a hardware failure on both machines (either is possible if these machines are 10+ years old).

You could also try the old V4 release of MemTest86, which doesn't require UEFI.

Old MemTest86 downloads are at the bottom of this page
https://www.memtest86.com/download.htm

[KD KD]

Ok thank. Will give it a try.

[KD KD]

I have downloaded V4 and successfully put on USB.
Now it seems to be running test successfully.
Thank you for your help.
To those who may search on this. My computer is a Dell Optiplex 990 With v24 of Bios. My experience is that you need to use V4 of the memtest896. That the newer version do not work.

[David (PassMark)]

Thanks for the update. These machines probably had the very earliest version of UEFI firmware (which were buggy) and Dell never maintained the BIOS.