64bit W7 - All Drivers have to be digitally signed, but you can allow unsigned drivers
Digitally signed WHQL drivers have to meet certain requirements to be signed and verify the driver has not been altered since the driver was created.
Non digitally drivers have not gone WHQL testing, and could be altered by third parties. So in short how stable or possible future issues with non digitally drivers are anyone’s guess....
To enable non digital signed drivers you have to edit the boot options in the BCD store. If you do not care about the above risks you can enable this feature by following the instructions in the below article:
http://www.freeotfe.org/docs/Main/im...er_signing.htm