Program crash

I use a Windows 7, 64-bit OS, and I just had the Muscscore program crash.
I first uninstalled it, then reinstalled it, and it still won't open/function. Crash notice each time.
Upon one of these attempts, there appeared a prompt to "repair", which I tried, but still it won't open.
What steps should I take to be able to regain access to Musescore and all my files??
Thank you,
Douglas Clegg
music@dougclegg.net