If you want access to the individual files within your complete pc backup, then the built in Complete PC Backup in WIndows Vista isn't for you.  You can only restore your complete partition.

A caveat to the above is that I have heard you can mount the above backup file in Microsoft Virtual PC as a harddrive, which in theory would allow access to the individual files however this would require you have Virtual PC installed and I have not tried this.

Acronis True Image 10 is compatible with Windows Vista and allows you to explore the backup files in explorer.