Welcome to OCN.
Try using NVflash. One of these threads should work for you.
Flashing with a floppy drive
Flashing in Windows 32bit(Basic)
Flashing and modding in Windows 32bit (full Nibitor modding)
USB bootable flashing
FLASH GPU BIOS FROM CD
How To: Unbrick Your Bricked Graphics Card/Fix a Failed BIOS Flash
How to Flash Your Nvidia Bios with Vista x64 with a Flash Drive
I don't really want to deal with NVFlash. And according to the link, the steps for Vista 64 (assuming it's similar for W7 64) don't seem to result in a simpler process for SLI anyway.
But I take it that you can't use HDTuner to flash cards in SLI then? What if I just plugged in one card at a time?
What if I use NVFlash to flash from flash drive during bootup, can I choose which card to flash manually?
Basically I want a way to do this without switching my cards in their slots. They're water cooled and it's too much of a hassle to bleed the system just for this.
Edited by matrices - 7/25/10 at 8:01am