I always look at my Sage 50 data file *.sai file as being similar to an Excel spreadsheet. Uninstall Excel and the spreadsheet *.xlsx files still exist on my hard drive. There is really more than one file but the concept is valid.

Open your data file in Sage 50 and look at File, Properties to make sure the path to your file is not in the program's directory (under c:\program files (or x86)\Sage 50 ..... If it is (rarely possible), then you should move it somewhere else (File, Save As and save it to a folder like c:\Sage50Data).

Also, I thought you could just enter your serial number, Account ID and keycode into a Trial version to activate it without having to uninstall and reinstall. Is there not an option on the Help menu for upgrading or registering or activating that allows you to enter a serial number and keycode?