I know this has been discussed, but all the answers I found were a little ambiguous.
In addition to the latest Platinum, I have several earlier versions of Sonar. Can I uninstall the old versions without losing any other stuff I need or want?
 
Thanks for any help.

Hi. IIRC you will probably have to reinstall SONAR Platinum after uninstalling the older versions, as Platinum shares some components with older versions.
All the best.

Ps. You will only need to install the latest Platinum release, as updates are cumulative. 
 

It is likely you will need to reinstall something. It could be older plug-ins which are not part of the current version or a program shared between versions. Either way, it is pretty easy to get everything back. Don't expect to free up much disk space. Most of the disk space used by SONAR may be freed by deleted the tutorials if they are installed. I looked at X series disk usage some time ago http://forum.cakewalk.com/FindPost/3179366

WinDirStat (FREE) is a great way to get a look at per folder disk usage.
 
https://windirstat.net/