I need to reset the password

Flashing the firmware clears the password and all other settings.
1) Download the firmware (and manuals) from http://ftp.dlink.ru/pub/FireWall/DFL-500/Firmware/ 2) Install a TFTP server on your PC - I downloaded Tftpd32, another one is TinyTFTP by Solarwinds.net 3) to save time, unzip the firmware to the TFTP server's directory and rename it to image.out 4) connect the DFL-500 to your PC using a null modem cable and use any terminal program (HyperTerminal in Windows, Minicom in Linux, settings 9600-N-8-1) 5) connect the DFL-500 either to your LAN router (straight cable) or your PC (crossover cable) 6) boot the DFL-500 by plugging in the cord 7) you have three seconds at the "Press any key..." prompt to hit a key 8) when prompted, type your PC's IP and make one up for the DFL-500 (according to the directions, you should change your PC's IP to 192.168.1.2 and use 192.168.1.99 for the DFL-500)
Here are some sample boot messages: FGT-50(11.04.2002) Ver:02080001 SerialNum:FGT-XXXXXXXXXXXX SDRAM Initialization Scanning PCI Bus...Done. Total RAM: 63M Enabling Cache...Done. Allocating PCI Resources...Done. Zeroing IRQ Settings...Done. Checking IRQ Routing Tables...Done. Enabling Interrupts...Done. Boot Up, Boot Device Capacity=30MB. Press Any Key To Download Boot Image. ...
Enter tftp server address [192.168.1.168]: 192.168.0.24 Enter local address [192.168.1.188]: 192.168.0.254 Enter File Name [image.out]: MAC:00:05:XX:XX:XX:XX 100Mbps full-duplex ####### Total 7678257 Bytes Data Is Downloaded. Verifying The CF Image.
Total 29500kB Are Unzipped. Do You Want To Save The Image ?[Y/n] Programming The Boot Device Now. ............................ Reading Boot Image 918457 Bytes. Initializing Firewall ...

DLINK-500 login: admin Password: Welcome!
Type ? for a list of commands.
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reset the router to default settings by pressing on the reset button for ten seconds. (usually located at the back of the unit)