PV+ has been through four actual generations of firmware, even though only the minor revision changed in three of them.
3.0
3.1
3.2
4.0
Version 3.0 of the PV+ firmware used a base Windows CE operating system that was version 3.0, and all the later versions of the PV+ use a version of Windows CE 4.10, aka "CE.net".
Version 3.0 must be first upgraded to 3.1 before it can be taken to any other version.
Because of Microsoft licensing terms, every unit that was upgraded from version 3.0 to 3.1 needed a new OS license sticker, and it was a chargeable upgrade.
RA did not charge for these for about a year, then started charging for the upgrade kit. Most RA offices still have a few of the upgrade kits around.
I do recommend contacting your local RA office and getting the firmware upgrade to the current 4.11 release of PV+ firmware. It's faster, more reliable, and has more features.
In the near term, though, version 4.0 of RSView Studio does have a "save as" feature to create a runtime that will run on any of the earlier terminal firmwares.