Tested on WXP (MicroXP, actually) as well.

I had thought that 1.0.x and the latest versions had different directory structures for the binaries, but it turns out that that's NOT true for AVR. However, some of the intermediate versions (1.5.0 - 1.6.4, I think) DO put even the AVR compiler in %APPDATA%. Unless configured for "portable" operation, in which case things are different again... The script does not currently handle %APPDATA% possibility.

I suppose that once this is working to my satisfaction, I should think about having a similar tool that installs any other compiler that the Arduino Board Manager has fetched. OTOH, that may be disappointing, because (for example) the ARM compiler has limit chip support included, and might end up with really nasty include paths needed to fetch even those...

I'm trying to remember if any of my systems will run W7 without a disk swap... :-(