Saving Windows 7 before Upgrade

Hi,

I have Windows 7 on my laptop. I am going to upgrade to Win 8. I do not have a Windows 7 CD. I know you could upgrade and do a rollback or even dual boot but is their a way to create a Windows 7 Installation CD from my current version? I would rather wipe the computer clean and install 8 versus migrating files over. Please let me know if this is possible.
Thanks!