The link here is for the Freelancer .iso. You'll need to mount the .iso to a "virtual drive" to install it. I use Ultra iso myself. It's free and never had a problem installing any .iso files. The only other issue I'm aware of concerning Win 10. is the need to have something called "Direct Play" installed? Haven't had to deal with this myself, as I still run Win 7.
1. Right click Start
2. Click Programs and Features
3. Click Turn Windows features on or off
4. Make sure there is a check in Legacy Components
5. Click the + to expand
6. Check the box for DirectPlay
In Windows 10 you can mount .iso files directly in the explorer. No second programm is needed anymore. Either doubleclick it or rightclick and select something like mount as virtual drive. Then you have the new drive and can install as usual. Should even run more rapidly.
I bet you installed Disco and Freelancer in your program files folder. If it's the case, you'll need to choose a "non windows" folder: as in not the desktop, not program files and so on. Go for one you made yourself.
If it's not the case, then nevermind.