How is your HDD setup:
1) Best method is two partitions, one for the OS and your programs (C-drive) ussally about 200 Gigs is fine, and a 2nd partition (a D-Drive) The rest of the drive for ALL of the files generated. This greatly simplifies imaging the OS, and backing up your data.
.. Using Windows 7 BU (located in control panel) windows will image EVERYTHING that is on the C-drive plus it will inclued the Very small system partition (Around a 100 Megs) that contains Boot info. To restore your operating system you can either use the repair disk (When image is completed you will be prompted to make a bootable repair disk) or You can boot to a windows installation disk and select repair, repair using image.
This will reinstall the image and you will boot into windows EXACTLY as it was when you created the image - No re-install, no reload drivers, no waiting on windows updates, and all programs are their.
You only NEED to redo this image when you make changes to the OS (ie add programs) maybe onece every month or two. You would use your normal backup program to bach up YOUR data from drive D.
2) If like many, Your WHOLE drive is c-drive. In this case the image that windows creates will include EVERYTHING, and EVERYTHING would be restored when you repair using this image. Probably do this once a month, so that if you have a HDD die, you can restore from this image and EVERTHING will be just like it was - Restore image, reboot and start using the computer. Any data you created inbetween last image and HDD failure you could retrieve from your normal back up.
PS: You can ONLY restore this image to the same HDD, or a NEW diskdrive that is the same size, or larger - Can NOT restore to a smaller HDD.
Hope this helps. - From a 70 year old senior - LOL