Small world since I updated another router just a few weeks ago. The bin file is used by the router to update it's firmware.
At no time did I open the bin file. Please use Dlink's instructions on updating. No forum moderator will tell you exactly how due to the possibility the instructions change and a post here could brick devices.
So no, you don't open this one.
A couple years ago I got the DLink pocket router and was trying to set it up again but I lost the CD. The shipping firmware can be found on the site, here is a link to the download: ftp://ftp.dlink.com/Wireless/dwlg730AP/Firmware/dwlg730ap_firmware_100.bin.
I have tried everything to open this file. I always get the "Windows cannot open this file" error. If anyone can help me out here that would be great, thanks.