I mended the non-operational windows on my S4.
I'm a bit too much on the large side (height and girth) to be contorting upside down between the steering wheel and the seat while trying to shine a torch on the fusebox and keep my reading glasses perched on my nose. Also getting far too old for such gymnastics!
Some idiot (probably me) had put a 10 amp fuse in the box and it had burned out. I only deduced this after I'd taken the card off the door to see if there were a jam in the mechanism. It was only then that it occurred to me to check whether the other window was working. A lesson, methinks, in being methodical.
OTH, just as well I bought a full set of auto fuses on a whim only yesterday...as I had no 25s in my current inventory.
1991 Spider S4 & 2004 156 GTA Selespeed