LightSpeed

I want to reinstall P3DV4, FSUIPC5 (Paid), PMDG 737, ActiveSky & ChasePlane on a separate SSD (Like This - see: https://www.youtube.com/watch?v=p-UHLwozSQc&feature=youtu.be Will this work? and if I uninstall it from my current "C" drive, will that invalidate my application?

I purchased FSUIPC4 from simMarket on March 04, 2010 and recently downloaded and installed the newest version. When I tried to register the new version my older version was deleted and the registration failed because it did not recognize my Key as valid. I have been unable to restore the previous version, however, I can uninstall the new version and reinstall the older version, but that might not work either. Is there a solution to this problem? When I installed the previous version in 2010, I was running Windows 7 or 8, but I am now running Windows 10 Pro 64-bit.