(If you want, I can produce a sample Inno Setup or NSIS script for an installer matching this description.)
Secures the gameplay environment from malicious software. grandrpinstallexe
Open Task Manager (Ctrl + Shift + Esc). Look for any process named grandrp* , installer.exe , or random strings of letters. Right-click → Open file location → Delete the folder. Then run regedit (Registry Editor) and search for "grandrp" to delete any leftover keys. (If you want, I can produce a sample