I have created and stored a system image using the Windows 7 imaging capability and successfully restored a disk several times. They state that older images will be deleted once you use 30% of the backup disk space. Has anyone seen that 30% figure in practice? I have never seen more than one system image on my 500 GB backup disk even with nothing else stored on the disk. My image size is currently about 30 GB. The 30% figure would suggest that my backup disk could hold several images before reaching the 30% threshold at 150 GB.