There's a simple protocol to follow to install STFD on your computer, and it works beautifully for me. I have Windows 7 on my computer, but I am still able to run all games (even the original SCK).
Instructions are simple:
1. Create a Folder in My Documents named Nancy Drew
2. Inside of that folder, create another folder entitled Secrets Can Kill (or whatever game you're installing).
3. Insert CD and begin to install game
4. Proceed as usual with installation until it prompts you to choose which folder under which it should install the game. Usually, it prepares and names a folder for you. This is where the tricky part comes in.
5. Click on the explore button to find the folder you just made for Secrets Can Kill (whatever game), and choose that folder as the one to install the game into
6. Upon finishing installation, open up the folder on your computer. There should be an icon entitled "AutoPlay" or something along those lines - the actual application that links to the game.
7. Right click on this icon and scroll down to properties. There should be a tab or a link somewhere in the properties menu that says "compatibility"
8. Click on the drop down for compatibility (or however it is on your CPU), and select "Run this program with Compatibility for Windows [insert program here]" For Secrets Can Kill you would select "Run this program with Compatibility for Windows 95/98" and after doing so click Apply on the menu
9. This usually takes care of the compatibility issue, but you may have to adjust your color settings to a lower BIT level if you want good quality.
It sounds like a pain, but once you do it enough times, it becomes second nature. And it's rewarding to feel like you cheated the system and can still play old games. ;) Hope I helped anyone confused!