In my opinion, it's not at all practical to convert to 4WD, there's the drivetrain (transfer case, front differential, drive shaft, axle shafts, wheel hubs, (maybe) front shocks, then sensors and wiring and module and dash switch and bezel with the hole for the switch... and probably more I'm not thinking of at the moment (did 2WD versions come with skid plates and exhaust shields?), on a vehicle not worth much over $1000 now (depending on condition).
I suppose if you have the free time and a donor vehicle it wouldn't be as bad but then they're old used parts. I'd sooner sell it and buy one with 4WD or really a 5.0L with AWD.
Window motor has probably worn out plastic pucks in its gear housing so it slips internally. Disassembly would reveal that, you can replace those pucks with a Dorman kit available at many auto parts stores or of course replace the whole motor assembly. You may want to lube the window track too as it may have been extra resistance that chewed the pucks up.
There's probably video(s) somewhere on youtube about this.
I think this is the right pucks but you'd want to take yours apart to verify that's all that is wrong:
https://www.autozone.com/interior/w.../dorman-window-regulator-gear-plug/426078_0_0
https://www.amazon.com/Dorman-74410-Window-Regulator-Gear/dp/B000CO96SG
Of course it's possible there is something else wrong after 24 years, worn out motor for example.