New: Wise Duplicate Finder (Jan 23, 2023), Platform 23.1 (Jan 11, 2023)
450+ real apps (49GB), 1 billion downloads, Please donate.
As noted, LOCALAPPDATA\stellarium is left behind on your system when run.
I have tested on a clean Win7 system.
Fortunately, there's a simple fix that can be implemented for the next revision. See here.
This is fixed in Stellarium Portable 0.13.0.
Sometimes, the impossible can become possible, if you're awesome!