Greetings, on a fairly regular basis, the power windows fail to work. After disconnecting the battery for a few seconds, they all work fine. Does anyone know why & how to fix, thank you

 

Several issues may be present.

let's start with more info on your vehicle.
Year. Submodel.
Does it have a factory or aftermarket security system?
Does/did it have a KeyFob?
Is it stock and have you bypassed any of the original wiring systems?

 

1999 Grand Cherokee, no to wire mods & security system. Am having SKIM issues wondering if it might be PCM issues

 

I might add that the SKIM issue is also by passed by diconnecting the battery

 

Ooof.... My experience ends at 98. I don't know anything about SKIM. Hopefully someone here has the knowledge.
A lot of these electrical components are prone to failed solder points at this age. You may inspect and repair if you're capable.