Once you adjust the memory straps save the bios and copy it to the atiflash folder. Flash the bios to your card with:
atiflash -p -f 0 MEMSTRAP.ROM
After it finishes loading the bios, don't reboot as it asks you to. Since you are using a modified custom bios and the new AMD drivers since 16.12 check for a valid bios signature, you need to patch the driver or use a driver older than 16.12 for Windows to recognize the card. To patch the driver download atikmdag-patcher:
https://www.monitortests.com/forum/Thread-AMD-ATI-Pixel-Clock-Patcherand use it to patch the driver before rebooting.
Assume Jesse is an idiot, and didn't know this. Jesse hypothetically rebooted before doing this, and now one of his cards wont boot -_-. Is it safe to patch the driver (on the other bios on the same card using the switch) and then switching back?