I don't want to see unsigned driver warnings while installing a driver, so I'm trying to digitally sign a driver using signtool, inf2cat, and a Software Publishing Certificate. Vista x64 requires the drivers to be digitally signed or it flat out rejects them, but I have managed to get Vista x64 to accept the driver, so I know I'm doing the process correctly.
However, I repeat the process for the Windows XP x86 driver. inf2cat and signtool both return successful results, signtool verifies the digital signatures, right-click -> properties on the file verifies the digital signature too.
However, when I go to load the driver in Windows XP, it still prompts me with an unsigned driver warning. Why does XP consider the file unsigned, but Vista does not?