Low disk space caused by Terminal Services

I have just installed windows 2003 on a new Fujitsu Server with two 36GB SCSI that are mirrored. Drive C is partitioned to 8GB in size for the programs and drive D is partitioned to 26GB in size for the profiles and data. Drive C has only 3.5GB of programs installed, however it reads that only 200MB of space is avaliable. When I manually search the drive I cannot find 7GB of data at all, it is like the other 3.5GB has just disappeared. Please help.