Windows XP Windows Vista Windows 7 : Download Link
Windows 8 Driver:
1. You can get the driver from windows automatic Updates OR
2. Download this drivers from Microsoft update catalog: Download Link
3. Extract the driver using winrar/winzip/7zip etc. Remember the path of the extracted driver folder.
4. Open device manager and look for network controller, it will look something like this:
5. It should marked with yellow if it not yet installed, right click on it and select update drivers. Example in the picture and it would not look like exactly the same, just for eaxample.
6. Right click and select update driver, select "Browse my computer for driver software" and select the driver folder we extracted earlier and continue with on screen installation until it finish install s and reboot.