The CDs on which Microsoft products are distributed are pretty much
identical, and as such, could be copied. Microsoft's protection is
based on the Product Key printed on the sticker you'll find on the
back of the case. Losing this is more critical than losing the CD.
If you still had your Product Key, I believe you could just borrow
someone's CD and install from that using your own Product Key.
As such, losing this number is tantamount to losing the software. In
future, be sure to keep a copy of this number in a safe place.
The only solution I would see is the contact Microsoft and have some
proof of your purchase. Only that way could you recover from this,
assuming Microsoft chooses to favor you in this matter.
Tom Ellison
Microsoft Access MVP
Ellison Enterprises - Your One Stop IT Experts