You need to be able to access the Linksys router with a wired or wireless computer.
Get yourself a USB key.
Surf to https://www.grc.com/passwords.htm
(Yes, it's a secure page)
In the third box down (63 random alpha-numeric characters), copy the entire key to Notepad. Save this file as wpa_key.txt and have a copy on the USB drive.
Type 192.168.1.1 into your browser. Enter the password, which is probably 'admin', unless it's been changed.
Under the Wireless tab, Security mode, choose WPA2 Personal. Under that choose AES. Under Shared key, paste the key you've saved to wpa_key.txt. Change the SSID to something you'll recognize, but not your address and not your name. Let's call the SSID "jmw9", for example.
Save your changes.
Now, take the USB key to each wireless laptop, and try connecting to jmw9. It will prompt you for the key. Simply copy and paste, then click on Connect. It should work now, unless the router has been configured to filter MAC addresses, which does happen.