Can't boot, documentation is contradictory. What's the problem?

[sgodun]

Got an old Pentium 4-based Dell PC that I'm trying to run MemTest86 Pro on. I've purchased and downloaded the v8 image and used imageUSB on an 8GB SanDisk flash drive to create an allegedly-bootable drive. When I attempt to boot the PC, I get a black screen with a blinking cursor in the upper-left corner. Nothing more.

This is a BIOS (not UEFI) machine. According to the readme that accompanied the download, "On machines that don't support UEFI, the older V4 BIOS release of MemTest86
will be automatically booted."

However, according to the PDF documentation that accompanied the download AND the online documentation, "All MemTest86 images support booting only in UEFO mode." Also, "If (1) is true (1="You have an older system that does not support UEFI") your system will not be able to boot MemTest86. You will need to upgrade to a new system that supports UEFI in order to run MemTest86."

Clearly these are contradictory statements; the readme file says it WILL boot into an older version, while everything else says it WON'T boot. Which is accurate? Assuming the readme is accurate, why can't I boot this PC?

[David (PassMark)]

V4 of MemTest86 was only for traditional BIOS

V5 to V7 of MemTest86 was dual boot. V4 would boot from BIOS, V5+ would boot in UEFI.

V8 of MemTest86 is UEFI only. But you can still download V4 separately. This change was made as many users didn't read the documentation and were confused by the dual boot setup, and accidentally booted the old V4 release on new UEFI systems (then got upset & sent abusive Emails). Being dual boot also made the packaging and testing more complex.

See,
https://www.memtest86.com/support/ver_history.htm

Any mention of dual boot should be removed from the V8 documentation. But the V7 docs will still talk about dual boot.