Here's some other information that might be helpful to someone smarter than me:
- I regularly use the exact same script and AutoHotkey version on a windows 7 machine at my work and it works fine. I'm using system cursors not custom cursors.
- The two DLLCalls in the code, SetSystemCursor and CopyIcon, both return nonzero values (on the Windows 10 machine) which means they completed successfully.
- I am using AutoHotkey Unicode x64 (on both the Windows 7 and the Windows 10), but also tried it with all the other versions of AutoHotkey and even basic, with no success.
- SetSystemCursor has been broken on my windows 10 machine for a while, but I do think it used to work. It's possible it stopped working around the time of the creator's update.