Nerazzurri, an important piece of advice....
Do Not install, or uninstall, any mods while at sea. Only install them while you are
in port between patrols.
Get and use JSGME for your mod installs. SH3 Commander 2.7 is also a very good thing to have and use.
And to keep you mods safe, burn them to a DVD or put them on a separate HDD used only for storage.
And last but most important... get GWX. You'll be glad you did even if you have to wait to use it once you can upgrade your system.