buying used pro 99 to network

I to have two networked computers and want to be able to use Quickbooks Pro 99 in a musti-user environment. I've been using my single copy for a long time and am satisfied with it.
Neither Intuit nor any other supplier I've found sells new copies of Pro 99 anymore. However, I've found used copies of ebay that have already been registered, but come with the registration number and key.
Does anyone know if that would solve my problem?
Thanks, Libby

[Mary]

Hi Libby. I also have two networked pro 99's, and want to add one more computer. I would be interested in the answer to your question. Please let me know how it works out. Thanks, Mary
My e-mail is TruckAccs@aol.com