I'm exploring the system image backup feature of Win 7. Never messed with any kind of image backup before, so excuse the newbie questions!

1. the amount of space it claims to need to create a system image is quite large. I think it's actually a bit larger than the occupied size of C: - is that normal? I read that Win 7 doesn't compress much - does that make for a more robust backup or is it just gonna take more space with no benefit?

2. I want to make this external hard drive bootable - i.e., in the future if I ever have to restore the image, I'd rather reimage directly instead of first reinstalling the base Win 7 and then going to recovery. Is that possible and if so, do I have to do anything specific to the drive and/or system image settings?

3. About how long does it take for say 100 Gb?