I just replaced head gasket on 4.3 liter V6 1995 chevy blazer

make sure you check your ground wires

If windows are electric, check switch and replace if needed.
Check window motors wiring connections. If motors are bas, replace as needed.
If manual, window could be off track or cranking mechanism may be broken. Replace as needed.
If light fuses are good, replace bulbs to the lights.

It sounds like you have a bad cable. When you jump it try putting the negative cable on the engine somewhere (metal). If that works your ground cable from your battery to your engine is bad. If it doesn't work check you positive cable. If you try cranking it when it's dark, and there is a bad cable or connection, you may actually see a spark where the bad spot is.

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Check the ground wire on the engine block? Make sure it is tight...

the best way is to have the radiator gases analyzed this will tell you if its a head gasket issue for sure and if so when you have it all apart send the heads to a machine shop for x rays to see if they are cracked. Matco tools sells a gas analyzer kit that anyone can use for about 60 bucks.also others on the web.

Try changing the distributor cap, rotor, plugs and wires

you have to remove the cover over the torque converter 4 bolts holds this on .you may be able to just move it out of the way. and yes it does sound like a starter problem.i hope this helps

check you fuses and clean your battery terminals, you might have a relay that controls you ignition. or could be your coil pack.

Well odds are that your blazer is fixed by now. Either way sounds like a bad battery, that's why you need jumps all the time. Why it would die, there are too many possibilties off hand. So what was wrong with it?