Cubase 7.5 01 not loading

I’m running windows 7 Cubase 7.5 64bit acts like its loading, gets all the way to the end then gives me a message
that cubase is not working. In fact if I watch windows task manager it says cubase not responding immediately.
I’ve reinstalled deleted everything i could get rid of. BTW cubase has been run on this machine in the past though its not my studio machine so i use it rarely.
Just for kicks I downloaded Reaper which works as expected. Any ideas?