MTH800 - not recognized by CPS

Hi guys,
my first post here. I am a HAM just exploring the world of Tetra radios for the first time.

Hopefully someone can help me figure this one.
I have come by some old tetra handhelds and I am trying to read them and program them. One MTH800 is not being recognized by the CPS (7.3). CPS sees that there is a radio connected but it is shown as a unknown model and it can not be read.
What could be the problem? Is maybe the CPS too old or to new?
Unfortunately I don't know much about the history of the radio, all I know is the radio software version (R07.000.5343).

Thanks!

Yes, you are using 'too new' CPS+ release.

The actual radio is around MR5.1.x so you should use legacy CPS R6C.246.07 or MR5.2 R6C.273.01
You will need to upgrade radio to be able to use it with recent CPS+ and import release packet (rpk) corresponding to the radio's FW

The latest FW available for this model is around MR5.14.10

Thanks for your help!
If I understood you correctly I should install a legacy CPS and than upgrade the radio!?

I can not find the CPS anywhere, could you please help me with the search or maybe someone here has this software somewhere on their computer?

I managed to get an older CPS (r6c.417.01) but there is another problem. Drivers for the usb cable are for WinXP, and I have 64bit Win7.
Is there a know solution to this problem?
Thanks a lot!

Yes, you could use RS232 cable !

Windows 7 could host 'XP Mode' too...

OK! I managed to read the radio using win xp on a virtual machine. It works ok!
Can you guys please tell me what is the oldest firmware version for mth800 that is supported by the CPS that I have installed and that I use for other terminals (version 07.30.09)?