Hi Ryar,
Thanks so much for your help in pin pointing to the directions and upgrade.
I did exactly, what the post said, but looks like I have to download more than two Win*.BIN CKS.. files.
I did copy the downloaded 2 files in SD card root and even came to service menu for upgrade (with SD card (Format) option), but the process was stuck on step#6 (Reading 100% completed) and it never moved further to writing step.
I went to the first post of the link you had posted, and it looks like that I have to copy more than just 2 files, but the download appears to be not meant for AVICF500BT