The HTC EVO 4G has a wireless chip inside capable of 802.11n. However, for some reason a software change limits it to slower wireless speeds.
The guys at XDA developers have again been busy and managed to create an update that re-enables 802.11n on the HTC EVO.
To run the code change you need to download a HEX editor and make changes to a certain file. When editing the file, all it takes is a few character changes and a save and re-upload to the phone.
Before you make any changes to a smartphone you need take a read over the instructions and make sure you have anything in order. This particular change appears to be relatively simple although we still recommend making the correct backups and proceeding with caution.
An update to the post has just included a link to where you can find the updated file preventing the need for you to edit it yourself. Full details at the link below.
Full instructions can be found over here.
Good job xda-developers