When I click on file or edit I get error message: arithmetic overflow and the program does not install in FSX?
I am assuming you are trying to run the old free EditVoicepack X? If not, please edit your question and provide details on which program you are running (name and version), and what you mean with “click on file or edit”.
Unfortunately the old EditVoicepack X had an error in the code it use to detect if it needs to ask for administrative access before modifying files. The error was not visible before the release of Windows 8 (as far as I remember), which is how it got released in the first place.
The workaround is to start EditVoicepack X by right clicking and selecting “Run as administrator”.