Hi,
What you own is a license to use the software, not a lease. A lease has a
finite termination point and is paid for during use at regular intervals.
Same goes for pretty much any software you purchase, anything "closed
source". Open source software is owned by both no one and everyone (at least
in theory).
As to the license, there are many different types of these. The standard
retail license allows for one installation on a device, you can change the
hardware on this device as many times as you please and continue to use the
license in perpetuity. The standard OEM license does not allow for some
hardware changes, mostly only additions to the hardware (eg: you can add a
sound card, but you can't change the motherboard). If the user stays within
the terms of the purchased license, it never runs out.
--
Best of Luck,
Rick Rogers, aka "Nutcase" - Microsoft MVP
Windows help -
www.rickrogers.org