Intuit doesn't keep copies of any tax returns, sorry.  

Have you looked for the actual folder that the files are stored in?  Is the entire folder missing or is it there but all the files are missing?   Reloading the program wouldnt make you lose client files, seems like theyve gotta be there somewhere.  Maybe you just need to run the Homebase Database Maintenance so you can see the client files in the program again?

You may want to hire an IT person to take a look at your system and see if they can figure out what happened.

Consider investing in an auto backup program like Carbonite, less than $100 per year and can be a life saver.

Also, "shortcuts" are just that; a shortcut is your menu listing or one-click icon to the program where it was installed. A program icon would be linked directly to the program itself. Typically, Desktop icons are shortcuts (.lnk), which means you can make a new shortcut any time, and even put them in various access points, for convenience. They don't involve reinstalling the program. When you get an IT person helping, ask them to give you an overview of working with shortcuts, making them, renaming them, managing your computer using them. That helps avoid overreacting to these things.