If you wanted to wipe the computer and reinstall Vista, then your could do a clean install of Vista with your Vista installation disc to do so.
If you just wanted to wipe the computer and leave the HDD empty without Vista reinstalled, then you could use your Vista installation disc or Vista recovery disc to run a "clean all" command on the HDD to secure erase it.
Most people would use the install DVD to format the computer as suggested above. If you are with the C.I.A and have special security needs software such boot and nuke About DBAN | Darik's Boot And Nuke will be more than sufficient.