For this, your best bet is to open a command prompt. If you’re unsure how. Find the folder where your GenerateProjectFiles.bat lives. then in the address bar type cmd, then hit enter.
That should open a command prompt. The correct format for generating project files is to run something like:
generateprojectfiles.bat -project="F:\TestProj_4_25\TestProj_4_25.uproject" -Game -Engine
This will create a solution in your game project directory. Just update the uproject path in my command above to point at the one on your harddrive.
Hope this helps.