Good question, I've never tried it on windows. But it is possible to do on a mac computer. Mainly because on OSX all the program's files are within the program package. Whereas, on windows it's a little different, such as registry additions. One issue you might find however is with a different version, the incomplete files might refuse to load when loading the earlier version. If the earlier version is LW 4, that's not a big issue, you can resume them from incomplete folder in library window.