How to update a driver when I can't connect to internet?

Go to control panel/system/device manager and find your device...you should have an option to "update drivers"

Get a LAN cable (ethernet cable) and use it to plug your laptop directly into the router. You will get an instant connection to the internet and should be able to retrieve the missing drivers from there fairly easily.

Another option is to go to a friends house and use their internet to download the required drivers. Stick them on a data pen or burn onto a CD.

Hope this helps