If you have a 64-bit version of Windows, you'll want to read CapnScurvy's thread
Windows10; Large Address Aware; SH4 Install. Sometimes, all a person needs is some more RAM to work with on their computer. He speaks to Windows 10, but it works in all 64-bit versions of Windows. The Museum eats up all sorts of computer resources - to the point that the game may not run after using the Museum, and the Museum usually won't run after you've played the game. This might be the only trouble...
However, just in case (forgive me if you already know this): the Silent Hunter games are installed by default into the "C:\Program Files (x86)\" folder on a Windows machine. That is a "protected" folder, and any edits done by you or JSGME to cfg and other files are rolled back by Windows. Your dds and some other text-based files stay, and can make it look like you have an activated mod, but you won't. If you are in a Program Files folder, you'll have to move the install one way or another.
I have Steam version of SH3 and SH5, and in both cases, I "Manage" my game installs in the computer's Steam app, not the online one. You log into Steam from the Start menu, Steam and do it there, as outlined in
Moving a Steam Installation and Games on the Steam site. It used to be that you could just copy and move the "common" folder of the game, but on my Win7 and Win8.1 machines, I had to do what they say on the Steam site. With the desktop, I "Managed" the move with the Steam app on the computer, and with the laptop, I had to "Move" things the way they say to...
