It's mostly as simple as:-

1. Downloading the official release binary of ScummVM and installing it.

2. Create a folder named "ScummVM" in wherever you normally store your games and just add each game by making a subfolder inside it, eg, "Maniac Mansion", "Loom", "The Dig", etc, and copying the relevant game data files or GOG folder there.

3. Run ScummVM and select "Mass Add" then point to the "parent" ScummVM game folder in 2 and it should auto-add all games in all child folders, without needing to manually add each game one at a time (though you could if you wanted).

4. I then back the whole lot up just by zipping that parent ScummVM folder (with all games included in sub-folders) plus backup %USERPROFILE%\AppData\Roaming\ScummVM\Scummvm.ini (that backs up the added games database plus all settings).

- "Reinstalling" games (eg, on a new drive) is as simple as installing ScummVM (as in step 1), skipping steps 2 & 3, and unzipping the files in 4 to the same place to "reinstall" literally dozens of games all at once (or however many you added) with settings intact. Playing games is as simple as starting ScummVM, clicking on the game and pressing Start. It's also possible to create direct Start Menu shortcuts using the following format (obviously changing the folder and game name for each game):-

"C:\Program Files\ScummVM\scummvm.exe" -f -p "C:\Games\ScummVM\Beneath A Steel Sky" sky

See above. It takes slightly longer to setup but once done and I have the game files I don't bother with the official GOG installers for future reinstalls as unzipping 40-50 games at once is many times faster than using 50x GOG installers (not to mention many games like Dreamweb or The Neverhood aren't even on GOG, so adding them as above is the only way to play them anyway). The same process can then be easily repeated for adding games to a micro SD card for ScummVM for Android (to play on a phone / tablet), then add ScummVM from the app store.