Gentlemen
I am having the same problems as those of the originator of this thread and several other contributors. The MP is not recognised by my PC when it is first plugged in. I have now tried it on 3 different machines, 2 off Windows 7 desktops and a new Windows 8.1 laptop. All these O/S's are 64 bit. They all behave the same in that a CD drive and a removable drive are installed but neither of these new drives are accessible. You have to refresh the drive display window for the drives to appear. I downloaded the Content Manager and installed that but that also does not recognise that the MP is connected. I tried another cable, not effect. I was beginning to suspect the I had a hardware problem on the MP's USB connector. I noted that another contributor had tried an old machine so I managed to get hold of an old Windows XP (32 bit) laptop. When I plugged the MP into that it created the same two new drives but this time the removable drive showed up as "Becker MP" and I could read the contents. The CD drive was still not accessible. When I tried the Content Manager again, it connected and I was able to upload all the software/firmware/map updates available, although this took some time (hours!).
Obviously this proves that the MP's hardware and the cable are okay. My suspicion is that the drivers that are loaded from the MP are incompatible with Windows 7 & 8, possibly only the 64 bit version, as I see that other contributors are using Windows 7. The support for the drivers appears to be non-existent as presumably Becker believe that they are universal across all O/S's.
Using the XP laptop is not a long term option for me so I am still looking for a solution to get the MP working with Windows 7 and 8 (64 bit). Does anyone have any suggestions I could try. Note that I have tried all of those already mentioned in this thread. Thanks for your help.