mentor pads on virtual pc
I never tried but it is possible.
If you have run both installation on the same SDD_HOME Directory the configurator file keeps tracks of all the versions. You have to launch it (it shuold be in SDD_ROOT\win32\configurator.exe) and then select the version you want to run.
If you have two SDD_HOME, before you launch one version you have to run the configurator.exe from the other version in unistall mode (from command line: configurator.exe -unistall) and then the configurator from the actual version normally.