how to share programs between windows 7 and windows 8?

Hello and welcome to the forums, mx73boy!

To put it simply, you can't 'share' them. (Unless you meant network or file sharing?)

If you want to use a program in Windows 7 you'll have to install it in Windows 7 using the program's installer and do the same again for Windows 8.

The only exception to this rule is portable software.

This is software that does not require installation or use of the registry to keep its own configuration data. To 'share' these programs between the two OSes, place their folders into a neutral data drive with the appropriate permissions set for your user accounts..

Leave the User folders on whatever drive they are on, then rightclick in the other OS to add them to it's related Library - Include a Folder - Windows 7 Forums.

This is easier than creating a data partition which is unnecessary with the modern convenient Library feature in both OS's.

Later when you want to get rid of one OS, just open the library (Docs, Pics, Desktop, etc) in either and drag all of its files into the other OS's user folder.