let you know about what?
if you dual boot, you will probably need to reinstall windows every now and again (due to it being shit). All being well, you should never have to reinstall linux.
Every time you DO reinstall windows though, it overwrites your master boot record (like any good virus should) without your permission, this means you cannot get into your linux partition unless you have a linux bootdisk that knows where you put linux. i think.
Anyway, i suspect restorrb is for restoring yr boot record to full health after it's been windowsed during a reinstall.