I am a Computer an d Cell Phone Flashing experienced person ( + i own 5800sm lol )
OK , sweetie the thing is Old turkey ( or whatever name is ) is exactly right. 5800 install any other Os , than the one it is intended to. Because the phone was manufactured in 2008 and the earliest Android was launched in 2010 !!! Therefore , this device cannot change its OS.
Explaination : Nokia has secured the bootloader of the phone . We cannot interfere with it . Therefore we cannot change the os !! simple...
What we can do : We can use the same Os , but make just a few customizations in the OS .. They tell you it is a new firmware , but it is the same old symbian s60v5. It is just like installing same windows again BUT with different skins ( changing of explorer frame and shell )
This custom configured OS is called CFW : Custom Firmware. It is provided largely on the internet. You can download and install it.
BUT PLEASE DONT FLASH YOUR PHONE !!! YOU PEOPLE ARE NEWBIES , AND DONT HAVE ANY NEED TO INSTALL IT.
still , if someone wants the risk contact me : hassnain.abdurrehman@gmail.com :) :P