I recently had a problem with a bad firmware update on my DrayTek 2820n router. For some reason the firmware re-flash didn't complete properly and the router could no longer be accessed via the browser web interface, even the DrayTek Firmware Upgrade utility and the TFTP programs did not seem to work. It turned out Windows 7 was blocking them and I had to turn off 'User Access/Account Control' (UAC). Here is how I did that:-
