If it's a wireless router it doesn’t need any software!
1. Can all the computers connect to the internet using the Ethernet cable?
2. If so, have you set up the router (192.168.n.n) with an SSID and a WEP/WPA key?
3. If so, connect by typing the key in hexadecimal rather than as characters. If you still cannot connect, go to the router’s set up (192.168 etc) and change the channel number and broadcast the SSID.
4. Switch the router of for a few minutes.
5. Troubleshoot wifi connections click here