I recommend that you phone contact your ISP support office and ask for help and information regarding this. If this unit was provided by the ISP, then it may have there own FW and support features which will need to be addressed directly with the ISP since it's there HW. We find that phone contact has better immediate results over using email.
Thanks for your answer FurryNutz, but I think I was not clear enough. There is no meaning for me to contact to ISP support, I guess. There are two reasons for this. First is that I live in Turkey, and I got modem from an Italian ISP, called Wind. They have no support other than Italian, and out of Italy. Italian people does not care about non-italian speakers at all, I had lots of trouble in a bank in Italy. Second is that I have to call Italy? That would be just waste of money. Plus, I do not think this is a problem with ISP. I just need to know the proper way to update the firmware.
You may ask why I did not contacted D-Link in my country. Well, the answer is that there were just ditrubitor in my country and Support link sent me here. Also, I couldn't find an e-mail to contact to D-Link directly. If anybody knows, please tell me just in case.
[SOLUTION]
I have solved my problem. I was able to update my firmware in Recovery Mode. I followed the steps in this
link. The firmware files from
here.
Note: Make sure to UNZIP .bin files. I did not unzip the .bin file at first, I choose it from inside of the .zip file, and the modem got bricked. At least, I think it bricked, because I was unable to access to modem ui, and recovery mode. Basicly, it was useless. I was able to get into recovery mode, but the interface wouldn't open. I followed th steps in this
link with original Wind firmware. To enable tftp command, I followed
these steps. After this, I got an error "Timeout occured. Conenct request failed." I repeated 3 times before I was able to access Recover Mode UI. After that I was able to update my UI to latest version via Recovery Mode.
If you have any questions about it, I will try to help. All corrections and extra information is appreciated.
Thanks.
ekardon