The 64bit version of Windows 7 requires a different build of the software as well. As you can see in the image below, you encounter errors while you run it. However, I have tried a way and it works normally.
Download and install DOSBox, then launch it. Extract the program archive to
C:\fractint then in DOSBox, type mount C:\ c:\fractint. Access the files using C: and then type FRACTINT.EXE. The program should run properly now.