I installed The Witcher EE on my Windows 10 laptop on a USB hard drive. On the laptop which it installed, the game runs fine. When I move the USB drive to my desktop and try to run it, the games does not launch. There is no error message; just nothing happens. I installed DX9 and MS VC++ 2008 runtime installed on my desktop, but still nothing happens. Changing compatibility mode and running as admin does not help Running the witcher.exe (rather than running from he launcher does not help . When I plugged the USB drive back to the laptop, I can run the game, so the game couldn't find something on my desktop that's on my laptop. Is it a registry entry or MS VC++ runtime other than 2008?

Yes.
All the configuration settings for Witcher 1 are in the Registry.
Computer\HKEY_CURRENT_USER\SOFTWARE\CD Projekt RED\Witcher\Settings (See Pic)
While you could manually add all the keys and values, it would be a lot easier to download the backup installers onto a usb and install the game on your desktop.

Thank you! Have to try it when I get back.