I cant connect the tablet to my macbook pro or desktop XP machine.
Also, where should it show 16gig? i only see about 9 or so, almost 5 of it already in use.
Yes, get a 16 Gig micro SD card (or 32, if you want to spend that much). And I think the trick to getting your computer to recognize it is to install the USB driver on your XP machine (not sure about the Mac). Get it from the Support/Download section of the Acer website.
I think part of the free space issue is that the system takes up a certain amount which isn't counted in the reported total free space. In addition, as with hard drives and other flash storage devices like MP3 players, 16 GB doesn't necessarily mean 16000 MB--it might be more like 14000 or so. To give you a couple points of reference, my 8 GB A100 reports 5.36 GB of total free space, and my 32 GB A500 reports 26.93 GB total free space.