How Important Is Fsb?

you will have to reinstall windows...

if it is an upgrade you may not have to reinstall windows but it is better IMO to format and reinstall window and will cause less errors
you willl have to put the chipset drivers and sound/vide if it is onboard but this wont prevent the computer booting into windows so you should install the mobo then the drivers as you would with any other component

@dray_02, I would like to know why you keep opening new topics.

Please answer that.

We were talking about motherboards in your other (several) threads so try keep it in one place. Thanks.