I have installed X2a and X1d side by side without any problem.
Can i leave X2 and X1 on my computer while installing X3, or is it more sure to make a clean install (i would prefer to keep X1 and X2, which are ok, with all their plugs also ok, etc) ?
Thanks you
TS
Nb : It is very pleasant to read all these positive reviews of X3, and to see that CW team is back !

Leave X1 & 2 installed. Skip installing DimPro, Rapture, "Loops and One Shots" (assuming you are running Producer), they are the same as previous versions.

All versions of Sonar can be installed side by side and co-exist. You are better off installing it with the other versions. That way it will share plugins from other versions.

I started a thread just a few days ago about just this topic. I'll see if I can locate it and give you the link.
 

http://forum.cakewalk.com/Time-to-house-clean-m2894766.aspx
Here it is! Wow, didn't seem like that long ago!

 
Thanks you a lot !!!