I'm having issues with my rig so I decided I probably should do a full hardware sanity check. I always start with Memtest86+, the very latest version.
I discovered that my computer resets while running Memtest if I move my mouse at all. A little googling shows that this is probably because I have USB legacy support enabled.
When I disable USB legacy support, I am no longer able to boot from USB flash though. A little googling shows that this is by design.
So I have three questions.
- Why is booting from USB considered a legacy feature?
- Legacy USB support also affects the mouse and keyboard (hence the reset issue during memtest). Why is this tied to the ability to boot from flash? Why aren't they two separate options in the BIOS?
- How does this not mean that USB flash booting support in Memtest86+ is completely broken? Is it only some machines having this rebooting issue, or is this a common issue?
I eventually gave up and burnt a cd with memtest86+ on it. When I booted it, I discovered that Legacy USB Support has to be enabled for my keyboard to work too. In the end, the final solution I settled on was to reenable Legacy USB Support and simply unplug my mouse during the test. It seems like a pretty crappy solution, but it did the job. I'm still curious about the design behind this if anyone has any insight at all.