Does built in Windows 7 backup perform differential (incremental) backups?

Solution 1:

Windows 7 Backup is a block based file backup.

This means each block in a file is examined and if a duplicate already exists on the last backup, and this is the important bit, even if from a different file, that block is not saved. Quite good :)

The first backup is always a full backup. The following backups will only save changed blocks. Disadvantage is you cannot manage your backups individually.