Thanks for writing!
I am really sorry to hear that the Control Panel removed your old product versions from the machine unexpectedly.
We currently work on an options menu (which is about to be released soon) which will contain an option for keeping previous parallel versions. I hope that this option will fit your needs.
We are constantly try to improve our products, so, please, let us know if you have any further feedback about the tool or any of our other products.
the Telerik team