AS5 takes whatever I paste into it and spits out a hex file ready to use, I don't really care other than that.
I know the project folder created as soon as you hit 'build' contains the .hex, but it also has a bunch of other files that aren't needed. I find it easier to save the hex directly on its own, give it a name that identifies it, instead of going through all the crap of naming the AVRGCC projects. Paste, build, save, then I'm done with it and don't want to see it anymore. I do all the editing of the input files in notepad beforehand, unless I miss something and it fails to build correctly. Even then, after I make changes and get it to go through so I know it works, I copy the source from the AS5 window and paste it back into the txt file I keep in the folders with each version of FW (along with a .bat file with the avrdude commands in it, so I can just connect to a driver and double-click, no futzing with opening command windows for me please, unless I just have to).
I have WinAVR installed, just because it automatically sets up avrdude - I'm sure there's a way to do it without the unneeded WinAVR stuff, but this works for now, it should work for anybody else who just wants to stick firmware onto a driver and isn't really interested in launching a new career as a (apologies in advance for the following link) software developer. I only care about this stuff to the extent it lets me make better flashlights. :p
Driver for the USBASP programmer is libusb-win32, again, no real reason other than because it works and that's really all I care about.