Out-of-the-box factory firmware upgrade
To install dd-wrt on either a D-Link DIR-300 Revision B1 or a D-Link DIR-600 Revision B1, you need to flash it directly from the router's web admin page (yes, that is correct... from D-Link's standard web interface). These are the steps to follow:
Download the latest firmware from:
http://dd-wrt.com/site/support/router-database , and enter the model as DIR-600 or DIR300 as appropriate. There will be two files, "dlink-revb-factory-webflash.bin" and "dir600-revb-ddwrt-webflash.bin" / "dir300-revb-ddwrt-webflash.bin". You only need the factory-webflash file.
Connect to the DIR-600/DIR-300 using an ethernet cable.
Open
http://192.168.0.1/ in your web browser, which should open the DIR600's/DIR300's administrative page from the standard D-link firmware.
The D-link's default login details are user "admin", password is blank, and type the captcha from the image.
Maintenance -> Firmware Update
Click "browse" button -> select the "dlink-revb-factory-webflash.bin" file -> click "Upload" button.
Wait 2 or 3 minutes for the DIR-600/DIR-300 to flash and do the update. (it should have finished when your browser tries to connect after the reboot, and probably fails because the IP address has changed). After the flash & update is done, the router will reboot to dd-wrt, and the IP address will have changed to 192.168.1.1. There is no need to do any reset.
Open
http://192.168.1.1/ in web browser. Will probably have to update your IP address (if using static IP) to this subnet to be able to connect. This should open DD-WRT's web interface. Configure DD-WRT as desired.
You're finished!
[edit]
Alternate Install Method using Emergency Room Web Interface Setup your PC with static IP on 192.168.0.0 subnet.
Make sure the PC has the following two files:
dlink-revb-factory-webflash.bin
dir300-revb-ddwrt-webflash.bin (or the 600 equivalent, depending on whether you have the 300 or 600)
Open your web browser and get it ready to connect to 192.168.0.1.
Press and HOLD the reset button on the router and connect power. Hold the reset button for about 3~5 seconds, then release.
Connect the browser to
http://192.168.0.1/ . The Emergency Room Updating Firmware screen should display.
Browse to and upload the first image file, the 'factory' one.
When you see the message "IMAGE UPLOAD SUCCESS", the flash will begin to be erased and re-written.
Wait until the power LED turns to solid 'Yellow'. At this point, the initial dd-wrt image has been written to flash, the device has rebooted and is running.
Change the IP address of your PC to the 192.168.1.0 subnet. Use your browser to connect to the router at
http://192.168.1.1/ The DD-WRT screen should load. If not, you did something wrong. Go back and try again.
There is a report that "emergency room web interface" may not support IE8, so if it does not work then try another browser: "Note that Internet Explorer 8 did not work for me on the emergency room web interface. It gave me a general page view error during the firmware upload. I had to use another browser to make it work (I used chrome but fire fox would probably work as well)."
[edit]
How to upgrade with new DD-WRT firmware
ссылка взята,http://www.dd-wrt.com/wiki/index.php/D-Link_DIR-600#Alternate_Install_Method_using_Emergency_Room_Web_Interface Удачи