When you restore a partition image to your Windows (C:) partition using Norton Ghost bootable CD, does it carry out a full format too?

It doesn't actually erase every bit/byte on the partition if that's you question. But files that were present before will be gone after (and definitely erased if physically overwritten).

100% of previous files would be gone? So absolutely no possibility of any viruses, etc left behind?

Say for example I have 100GB partition which has WinXP and other programs occupying a space of 10GB. I make a image of it using Ghost and sometime later due to some virus attack, restore that partition using the previously saved image (with Ghost). So during restoration if Ghost doesn't format the whole 100GB then there could be a possibility of the virus remaining intact in some sector.....right?

(and definitely erased if physically overwritten).

So does Norton Ghost physically overwrite?

Hello

The restoration procedure of Ghost, when you are using an recovery image will replace any backup bytes. So if your backup took 10GB, the restoration will replace the 10GB pattern including boot ....

If your backup is clean (without virus), it will be ok.

I don't remember as well, but with the boot cd i think you can use tools for hard drive : to do a "normal" format. It will be long but it will ensure no viruses.

Hope it will help you

So during restoration if Ghost doesn't format the whole 100GB then there could be a possibility of the virus remaining intact in some sector.....right?

Formating is a whole process, you don't format "part" of a partition, you format the partition or you don't.

This erases all files (100%). Whether those are physically overwritten or not is an other question and depends on the method and the OS involved, but to the system, they are gone, the partition is empty. In your case, files that have not been overwritten by your new image can be recovered only using tools that are not included in Windows.