Notes on Running CARA under Windows 10
We have installed CARA under Windows 10. We had trouble running it. At one point, it seemed important to set the Compatibility Mode flag (in Properties, Compatibility tab) for the two executables CARACAD.EXE and CARACALC.EXE. At another point, it worked better when we did NOT have the Compatibility Mode set.
Another problem is that CARA tries to display Help as soon as you run it. Microsoft doesn't want to support the old version of Help. If you don't do anything about it, every time you run CARA, you will get an Internet Explorer window showing you a web page explaining that you should use a newer version of Help. If you can close this window and not try to use the Help in CARA, you should be OK.
If you really want to try to fix the Help: Find a copy of Windows XP. Copy the file WINHLP32.EXE from the \WINDOWS directory of the XP installation. Forcibly stuff that file into the Windows directory of the Windows 10 installation. (This will probably require taking ownership of the existing stub named WINHLP32.EXE, changing its name or deleting it, then copying the version you extracted from an XP system. I've seen a forum post suggesting that a future security scan of your system may complain about the operating system being changed, and may automatically undo these changes.)