Yes you may the Dell Windows 7 Reinstallation DVD uses a Dell OEM System Locked Preinstallation key. This is automatically input and activated when a valid the Dell BIOS is detected;
My wife's Inspiron N7010 seems to have lost all it USB ports (no mouse, no way to back up, etc.).  I was about to reinstall Windows 7 to see if that would solve the problem but learned that I might need to enter the Microsoft COA.  Dell conveniently glued the sticker on the bottom of the laptop.  After a couple years of use, the label is no longer readable.  Wish someone had told me to copy the number down and save it.  Now what?  Can I reinstall Windows 7 from the reinstallation disk from Dell or not? 
Unreadable Certificate of Authenticity