If it didn't come with an installer you would go into the device manager and look for the listings under display adapters and right click on them to choose the update driver option. You should see a primary and secondary listing. If there is only one for your model card simply right click on that to proceed with the update where you will browse to the drivers whether on removable media or where downloaded to a folder. Windows should recognise and copy them right away. Upon restart of the system those will then be set active.