I bought another GTX 260 (216sp) today. Both cards are detected in the device manager , and in nvidia control panel. They are both connected properly to a new 750W PSU. Windows detected it and everything was fine. I restarted and I got error code 43. Device driver failed to load. Reinstalling the driver will allow the driver to work again, but then SLI cannot be enabled.
If I uninstall the driver, remove 1 of the cards, boot, power down and install the 2nd, I then can enable SLI, but only until the next reboot, after which I get error code 43 again.
Both cards works fine, I tested them. Could a newer BIOS fix the problem? Has anyone had this or heard of it? If anyone has any experience with this help would very much be appreciated.