I always save/copy my entire projects on an external USB hard drive…it does not matter if your machine takes a crap, your files will be backed up on another hard drive. In fact, I’ve had to rebuild a machine…when I copy my project files back on the rebuilt machine, the files open fine…although I had to re-direct each project due to a re-location thing, but only the 1st time. However this was with using the same Cubase version.
I’ve seen SX 3 projects open in C-5 fine (see below about ‘save as’)… I would think SX2 should open in C-5, I’ve recently read that you can open .cpr files of one version, in a ‘higher’ version, but not the other way around! There may be some strangeness, but you shouldn’t ‘lose’ anything as a result of it.
Again, backing up your projects to an external USB drive 1st. BUT…I would STRONGLY suggest that when you DO open your SX projects in C-5, or anything above SX for that matter, that you select ‘Save As’ and rename that song project…this way, you can still open that project in SX2! But if you forget, you always have the project as it was if you saved them in the external HDD.
Of course, if you’re using the same machine for multiple Cubase versions, I’ve read of a number of people over time, having issues with the license…it took some ironing out for them, and possibly a support ticket from Steinberg to get it going.
SAVE/BACK UP your projects!
PS, Hey man don’t feel bad, I’ve used Cubase VST 5/32 for 15 years!