Lets go here:
http://tsd.dlink.com.tw/downloads2008detail.aspSelect DIR from the left side drop down menu.
Select 816L from the right side drop down menu.
Download the following file:
DIR-816L B1 v2.03 for WWDo the following while hard wired LAN connected to the router please:Use IE or FF to do this.
Disable all browser security add-ons and any PC security SW temporarily.
Factory reset the router using the routers web page option under Tools/System.
Upload the DIR-816L B1 v2.03 for WW .bin file.
After the upload completes and the router comes back to ready, Factory reset the router using the routers web page option under Tools/System once more and then set up from scratch.
The UI should be in English now.
Let us know how it goes...