Hi ThatsMyName
you have not said if the Windows 7 DVD is a full retail disk, or Microsoft OEM DVD
(both have holograms)
(unlikely to be a manufacturers OEM DVD as should not be on retail sale, (no hologram))
and what version eg: Home Basic, Home Premium , Professional, Ultimate
(Enterprise should not be on sale)
usually Pro Retail has both 32bit & 64 bit dvd's and one key for one installation on one PC at any time
the OEM versions usually come with one DVD and can not legally be used on a different system
(unless MS allows change because motherboard has died and similar replacement is no longer available)
depending on the time between installations MS on line Activation will detect more than one installation and require...