I can't find much technical information on using full backup under Vista. I
am using an external hard drive for backups. Am I right in thinking that:

a) if you do a 'full' backup repeatedly to the same external drive, the
first time it will be a real full backup whereas later ones, though still
called 'full', will in fact be incremental?
b) if you delete the 'WindowsImageBackup' directory from the external drive,
will force the next full backup to be truly 'full' again (not incremental)?