|If you can slave the HDD into another computer, just copy the files. Are you talking about only the data files or the program aswell?|
If you can retrieve them and don't have access to SC4 anymore, I believe Lucid 3D could read SC4 files. Available here http://wareseeker.com/free-lucid-3d... as shareware.
Anyway the program files were only extracted to the HDD on install, due to them being delivered on floppies, so you should be able to copy them aswell, if you manage to access the HDD.
This is just a sig