Install CB7 over CB4 keeping CB4 ?

I am installing Cubase Artist 7 on a pc which currently has Cubase Elements 6 installed.
Is there any way to do this so I keep CB Elements 6 separate so that I can run it as it is
now without invoking CB Artist 7 ?
Reason I’m asking is in case I find problems with the new install of CB Artist 7.
Or are my fears unfounded ?
If it can be done is there any reason to do so, or should I just go ahead and install
CB Artist 7 per instructions ?

That´s what you should do.
There are plenty of “can I install Version x and Version y on the same computer” - questions all over the forum with just the same amount of basically always the same answer. The same applies to your case