First of all, 12.8.0 is an old version, you should try the version you can download from our website, 12.8.2.
If the problem persists, try running "atkpython" from the command line instead, just open a terminal (click Start>Run... or hit WinKey+R, and type "cmd"). Then type "atkpython" in the command window. That may provide additional error information useful for troubleshooting.