[YellowFin]

Here's what worked for me:

1. Install game via steam
2. Open C:\...\steam\common (where Silent Hunter 3 directory is located)
3. Zip Silent Hunter 3 (the game directory) using 7 zip or similar
4. Copy Silent Hunter 3.zip and paste to, say, C:\Games
5. Unzip Silent Hunter 3.zip and rename the output directory to, say, LSH3
6. Download Multi SH3 and use according to its manual
7. Test installation of SH3
8. Proceed with LSH3 installation