There are hundreds of Pavillion G6 models and many use different WiFi cards which require different drivers. Also, the operating system you are using may require a specific driver.
What is full model number of the laptop? The G6 models generally have 4 numbers followed by 2 letters (such as the g6-2132nr). Also, what is the operating system you are using? (Windows XP, Vista, 7, 8)