Maybe you don't. In control panel go to Device Manager. Click on the little arrow next to Network adapters. Right click the adapter and uninstall it. (don't delete drivers if asked) Then re start your computer & see if that repairs the bad driver.
If that doesn't fix it,(YOU MUST USE SOME WAY TO GET ON THE INTERNET) (plug in to your router or use a portable usb wifi adapter) repeat the same steps & rt click the adapter & Update driver & select Search automatically (not find on this computer) . It goes on line to Microsoft & it searches it's driver base & finds the proper driver & installs it. If it either finds a better driver or says you have the correct driver & still doesn't work you have a physical problem with the wifi adapter on the mother board. then you need to use a USB wifi adapter like this one. rt click & open in a new tab to view
Trendnet N150 Mini USB Wireless Adapter - IEEE 802.11b/g/n, 2.412 ~ 2.484GHz, 150Mbps, WPS, USB 2.0 (T156-2502)