Run the Wget and Mtd command line utilities included with OpenWRT to install DD-WRT router firmware on an OpenWRT router. Check the DD-WRT site to find the most current, stable firmware version compatible with your router hardware in preparation for the install. Access the OpenWRT router command console through SSH to install DD-WRT, and perform the DD-WRT installation via command line, which requires fewer steps and less complexity.
Plug one end of the Ethernet network patch cable into the network interface socket on the Windows 7 computer. Connect the other end of the Ethernet patch cable into an OpenWRT router LAN port.
Click the Windows "Start" button and type "ncpa.cpl" into the "Search" box and press "Enter." The "Network Connections" window will display.
Right-click on the "Local Area Connection" that displays a "Connected" status and click "Properties." Click the "Networking" tab.
Click the "Internet Protocol Version 4 (TCP/IPv4)" item and then "Properties." Click the "Obtain an IP address automatically" and the "Obtain DNS server address automatically" radio buttons. Click the "OK" button.
Click "OK" in the "Local Area Connection Properties" window. Reboot the Windows 7 computer.
Click the Windows "Start" button and type "cmd" in the "Search" box. Right-click the command line icon that appears and click "Run as Administrator."
Type "ipconfig /all" at the command prompt and tap "Enter." Note the gateway IP address listed in the command line output.
Click the task bar "Start" button and type "putty.exe" into the "Search" box. Press the "Enter" key.
Type the gateway IP address noted earlier into the "Host Name (or IP address)" field and click "Open."
Enter the OpenWRT SSH user name and password when prompted and press "Enter."
Type "cd /tmp" at the command prompt and tap "Enter." Write "wget http://www.dd-wrt.com/dd-wrtv2/downloads/stable/dd-wrt.your_firmware.bin" on the command line. Replace the "http://www.dd-wrt.com/dd-wrtv2/downloads/stable/dd-wrt.your_firmware.bin" with the URL of the firmware you want to install and press "Enter."
Type "mtd -r write /tmp/your_firmware.bin linux" at the command line. Replace "your_firmware.bin" with the name of the firmware you are installing and press "Enter."
Wait 5 minutes. Reboot the router.
Things You'll Need
Windows 7 computer with the PuTTY program installed
URL of the DD-WRT image you want to flash
IP address of the OpenWRT router
SSH authentication credentials for the OpenWRT router
Ethernet network patch cable