Do you have all the licensing and registration information? If so, it should just be a simple reinstall through either EMA-EDA or Cadence - I did it when I had to switch to Windows 10 from Windows 7, years ago and long after my maintenance agreement expired. If you have no backup copies of that information, then you're probably out of luck.
You do design work without a robust backup system in place? An external drive or cloud subscription is way cheaper than another copy of software, plus all the lost work...