Goto start menu, find the game, click on the uninstall option.
Or goto start-settings-add remove programs (might be called slightly different) select the game and hit uninstall

To re-install, download the files from the website, store them all in one folder, run the exe.

If your using galaxy I can't help you.

If you;re having difficulty with a game, it may be helpful if you mention what game it is and what the specific problem you;re having with it.

Ok, so it looks like your missing the particular C++ extension. Did you buy the game from GOG? Did you use the classic installers or via galaxy? Have you installed the game (as you should any software) outside the windows folders, e.g. c:/mygames?
If so then the C++ should be installed as part of the installer process (Heck I have about 15 versions of the damned thing installed on my machine now. You can always pick up the C++ runtimes installers from:
https://support.microsoft.com/en-us/help/2977003/the-latest-supported-visual-c-downloads

You can also try out the sub forum for the game:
https://www.gog.com/forum/neverwinter_nights_series/page2#1524672115

Which has lots of useful information, for instance:
https://www.gog.com/forum/neverwinter_nights_series/nwn1_andor_nwn2_windows_10

Just go to the game your wanting to uninstall and reinstall in there will be the more button. Click on that. Then go to Manage Installation and then there will be Uninstall. After that it gives you the option to Reinstall