Hard reset D-Link DIR-827

Factory reset (Hard reset) Power ON the router. Locate the reset pin hole – it is on the back panel (next to the USB port) and is marked with red. Use a paper clip to press and hold down the button for 10 seconds. Release. Wait 30-60 seconds to access the router. 
Firmware Firmware link
Default username admin
Default password [leave blank]
Default IP address