Right-click the icon you use to launch darktable, it will tell you where your reliable is installed. For example, C:\Program Files\darktable\bin\darktable.exe.
Copy that to the clipboard.
Click on the Windows Start button. Type:
command
That will give you an icon in the menu to launch a command-line.
Click on it, then paste the path of darktable.exe, but be sure to surround it with double quotation marks, for example:
"C:\Program Files\darktable\bin\darktable.exe"
Add -d lua to the end:
"C:\Program Files\darktable\bin\darktable.exe" -d lua
Press Enter. This should run darktable. Try to launch Gimp from darktable, then close the application.
Attach the log file here (I’ve already posted where it should be located). Note that some of the directories will be hidden, so you’ll have to set Explorer to show them. You can search the web or this forum, the instructions have been posted several times. This thread is an example: