|I assume, you're talking about an encryption key for your wireless network, don't you?|
For the router, you don't need a setup disc.
You simply need the routers manual, some time to read it and an Internet browser.
You have to type in the ip address of your router into the address line of your browser and hit enter.
Then you have to login and go to the wireless section.
There you can configure the encryption type and key.
All this is described in the routers manual.
If you don't have the manual, go to the manufacturers homepage and download it.
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