So on Windows 7 how do i access the device? I'm afraid I have never heard of the MTP format.
Please refer to the step by step instructions provided in the link below:
The Xoom does not mount like a normal flash drive/partition, instead it utilizes MTP to do file transfers. On Linux, I had to install the mtp-tools package to get around this. While command line, (example: mtp-sendfile) they're my style and work well.
MTP grants the Xoom potential encryption and DRM features (as well as not tying up the internal memory to the host computer) at the expense of a good out-of-box storage solution. I don't think it was a very smart move, but that's just me. I'd rather reformat the device to use all 32GB once the SD card slot begins working.
MTP is not a format, it is a protocol, a language for devices to talk to eachother. See http://en.wikipedia.org/wiki/Media_Transfer_Protocol for information on MTP.
Here's a common question to most MTP troubles: Are you connecting the Xoom via a USB hub, or directly to the computer?