Does reformatting your HD mean you have to completely reinstall the OS also?
& a question on System Restore: Would it get rid of any viruses before that set date?
Yes.. Reformatting in essence basically allows you to write over any existing information..
Then we have what's called the low-level format which basically zeroes out the whole drive (digital info is a series of 1s and 0s)
I always use Dban
http://www.dban.org/download and Nuke the entire drive.. They format the drive to D.O.D. standards..
And yes, you will have to completely reinstall your OS.. You'll lose everything, so be sure to back-up any files you need(music, videos, documents, etc.)
Programs cannot be saved and will have to be reinstalled as well.. Then you'll also have to do all the OS updates.. It's quite a bit of work..
There are a few different versions of system restore.. If you have a factory built system such as Dell, chances are there is a restore partition on your hard drive..
Windows uses this to put your hard-drive back to exactly the same way it was when you got it new (all with all the BS software they force on you)..
Basically, it ghosts an image of the factory installed OS and programs over to the OS partition of your hard drive.. If you don't have any restore disks or
an actual Windows disc, you should never format the whole drive, only the OS partition (unless the restore partition gets corrupted somehow)..
Windows system restore basically sets the system back to a certain date that you backed up or backed itself up..
This is usually a temporary fix and you will still have to reformat and reinstall everything.. Even after using Windows System Restore,
the virus will still reside in your system as well as your registry..