After compressing the mmc it shows only 511 mb?

Question

Hi My 2gb microsd memory card only offers 1.87gb of free space when its completely unused. So i fiddled around with it on the pc (windows 95) and when I saw the properties for the mmc there was a small tab labelled compression on the right, so when I compressed the mmc using Drivespace it said it will creat a host drive and my total memory after compression will be 2.7GB but after compression I only found 511mb of total memory! not even my original 1.87GB so i formatted it again and now im back to 1.87 GB.I'm guessing after compression when i checked the mmc on pc it only showed me the host drive not the main memory?I'm real confused on how to make this work.Please help!Thanks alot for your time.