The game simply generates a background process, and I don't know how to solve it. some solution

I got the solution in the following thread to work: https://www.gog.com/forum/pandemonium_series/win_10_support

Basically...

Download the newest nglide. Open with 7-zip and replace the files in the Pandemonium install folder
https://www.zeus-software.com/downloads/nglide

Download the winmm fix. Copy and replace the files in the Pandemonium install folder.
Rename "Winmm.dll" to "win32.dll"
https://www.mediafire.com/file/s5lypg970azzdmp/fixed_winmm_win10.zip/file

*I also tested it with this winmm fix if you prefer a different version. Install as above instead if wanted.
https://github.com/dippy-dipper/ogg-winmm/releases

Run "nglide_config.exe" if you want to play with the graphics options.

The game should hopefully now run!

Thank you so much, it finally works and I can play it again.
I have fond memories of this one and before I tried replacing nglide with dgvoodoo, which worked too but something was off, now that the playback dll is fixed it's perfect and for one I don't find nGlide underwhelming either.