Upgrading Motherboard. Reinstalling windows and Hard Drive?

[BrokenEffect]

I'm upgrading from an old ASRock Motherboard to a newer ASUS Motherboard
Is it possible to boot my computer once i complete the update, and keep everything on my hard drive?
Will I have to reinstall windows?
Will I lose everything on my hard drive?

What If backup my hard drive onto an external drive? Once i wipe everything on the upgraded PC, won't the drivers on the backup drive overwrite the new ones?

How do i do this?

Also: I have a CD with windows on it and a key.
Windows was pre-installed on this computer and the CD is for re installation, will i need to buy a new copy of Windows 7 Home Premium? Or can i use this CD with the key also?

And if i need to do that ^ Will it wipe my hard drive?

Please Help!

 

[clutchc]

If the boards have similar specs and components, it's possible to be able to boot to Win once the new board is installed. Not always, but sometimes possible. It will depend on the similarity between boards and how much background stuff you had installed. Might be best to pare down the old installation to the bare minimum before changing boards.

But MS will eventually notice the new board, and you will have to re-activate all over, if you have an OEM license of Win7. You'll then have about a 50-50 chance of them accepting the new board w/o issue and give you a new activation. If it fails, you'll have to jump thru a few hoops to get it re-activated w/o buying a new license. But it usually passes.

Once you get the PC to boot to Win7, I would suggest you let Win install its default drivers first, then run something like CCleaner to clean up the mess that the Registry will be in: http://www.piriform.com/CCLEANER
Then install the drivers for the new board.