Not sure. I just looked up WiFi max wattage and found that max was 1 watt.
radio and 4 watts EIRP (equivalent isotropically radiated power), if you're using an omni antenna. If a device is FCC regulated, it will be below this. The problem comes in when people start building their own setups. It's not too difficult to go over this with some of the stuff I've seen here on the board. Take the 1 watt amp, add a 6dbi omni to it, and you're at the max 4 watt output. You'll actually be just a tad under giving losses for connectors. You really should never use an amp on wifi unless it's absolutely necessary, and you know what you're doing. Even short term exposure from a one watt amp and a high gain directional antenna can damage your eyes, and other sensitive parts of your anatomy.
Failure is not an option....
It's installed by default on every version of Windows.