Installing a new version of Switch automatically removes the previous version of the same Switch product flavor. Running two versions of the same Switch product flavor at the same time on the same computer is not supported. This is because the two versions would share the same preferences and application data.
It is possible though to install and run multiple Switch product flavors in parallel, since each flavor has its own preferences and application data. For example, you could run FullSwitch 07 and PowerSwitch 08 at the same time on the same computer.