Hard reset TP-LINK TL-WA830RE

Factory reset (Hard reset) With the Range Extender powered on, use a pin to press and hold the Reset button for about 8 seconds. Release when the System LED becomes quick-flash from slow-flash. Wait for about 1 minute for the RE to reboot to its default settings. The System LED is the one that looks like a small gear wheel.  PS. If you have an older version of this Range Extender try holding the reset button for just about 5 seconds.
Firmware Firmware link
Default username admin
Default password admin
Default IP address