You get that message when using Ghost? That is weird, ghost doesn't give a damn what you have on your hard drive (well, the older versions use to give allot of trouble with NTFS partitions because of their fragmented nature but if you used the -NTIL switch, it was basically bypassed).
Do you have the error number on that message? What version of ghost are you using? and how are you trying to ghost (Network, Master/Slave etc.)