I never used Vista, but I am using Win7. I suspect Vista is similar. Do you have a folder called User? If so look in Appdata. Local, VirtStor, Program File x86 and finally Infogrammes.
If not, do a search for *.sav. In Win7 the Program Files folder is protected and, if you do not run C3C as Admin, it cannot write the save where you expect it. All apps will then default to the User folder someplace.