How can i use my buffalo router? how can i install it if my loptop does not have

Router don't need installed, per say. The disk just makes configuration easier. Read your manual and you should be able to find the default IP address, user name, and password for the router. You can then use your web browser to configure the router. So, if you manual says the defaults IP address is 192.168.0.1, you would open your browser and in the location bar type:

http://192.168.0.1

and it should take you to a login screen where you can use the default user name and password to get in. Don't forget to change your password once you are in.