OK; thank you Annie/weezer for your input and suggestion!

I have of course an external HD for instant work backup and the DVDRW so I'm well guarded from losing my Vue/Bryce and even Cubase files.
I felt a bit scared when I was thinking that only in Cubase alone I have 30 softsynths with their own user settings and saved files...it took "years" to install them and make them work not to mention the subfolders of Bryce and Vue.

Thanks for the tips, they were appreciated; I'm going to install these progs/folders during a longer period and will check out the mentioned GHOST app.