Windows Vista Home Basic backup?

In perusing information about backing up in Vista Home Basic, I learned that it's not possible to back up the entire C drive, only basic user files. When I first installed Vista, I was poking around all the features and I remember using the backup feature. However, I THOUGHT I had backed up my entire C drive. I remember the process taking a good deal of time, whereas backing up basic user files only takes a few minutes. I was hoping someone could verify what I may have thought I did. I didn't use a third party program.