It has to do with changes Microsoft made to Windows in 1995. Registry entries, shared DLLs and more make it nearly impossible to backup programs today.
As to formatting, that means the disk is formatted but no OS is installed. Be sure you read this link next -> http://forums.cnet.com/5208-6035_102-0.html?forumID=7&threadID=66200&messageID=995124
I'm about to reformat my computer (XP Home)and since I haven't done this before I have a couple of questions about backing up certain things.Can I back up programs like for example Nero?.Programs that that I don't have installation disks for or do I just have to get them later?. I've backed up pretty well everything I want to keep like "My Documents","My Pictures" and things like that.Is there anything that I should absolutely not forget to back up other then the things I mentioned?.Any help or suggestions would really help because as I said I've never done this before. Thanks Guys.