So it doesn't delete the OS, it replaces it.
The only downside is that if you forgot to backup your stuff, your stuff is going away.
Bob
I have a Dell Inspiron 1545 laptop and it has Windows Vista Home Premium. The problem started as a phantom internet connection that wouldn't load any pages. As I tried to cleanup my computers processes, I ended up restarting and trying to execute a system restore. But I don't think I had any restore points, for when I restarted, I tried to connect to the internet, but I was faced with, " the dependency group failed to start", even in safe mode with networking. I can't access any backup and restore options either. Is a Dell factory image restore going to delete the operating system too? because I can't let that happen, for I do not have the installation disc. Is there any way that I can return this PC to a functioning computer again?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic