Update

I haven't been using Musescore recently and when I opened up and received the message an update was available I clicked on the download and installed the updated version. I now have two versions on my PC. or at least I can still open two versions from my desktop. The old version cannot see the music I have written in the new version but the new version can see everything I have written, I think.....
I closed down Musescore while I was downloading the new version, was that a mistake.
Can I delete the old version in some way without loosing all my old music, I have quite a lot of it.