Hi,
Errr... I'm not exactly sure why you rejected my answer...???
I counted several freeware utilities on that site that would do what you wanted??!?!?
Here's another one.
http://www.stormloader.com/autobackup/
This one is shareware and after thirty days of use, the writer makes a "humble request" that you send him $10. Not much money. And.. a conscience decision.
It specifically mentions "differential" backups. A differential backup is even better than an incremental backup in terms of space taken... it only backs up the *part* of the file that was changed.
The other utilities on TuCows would do just as well.
If you're going to reject my answer at least you could let me know why. Your question specifically asked for "Is there any free software/utility to take such type of backup"
Cheers,
Tim.