Both electric windows simply stopped working. The fuse checks out ok. Any suggestions? Thanks

 

BOTH (LH and RH?) simultaneously!
Sure you got the correct fuse? this is the only component common to both circuits that I can think of.

If you are DIY competent check voltage at each end of the (correct) fuse to ensure the supply is OK.

If this is OK you will have to measure voltage at various points in the circuit. next suspects are SWITCHES and RELAYS but two circuits would not normally go down together.

Stuart