My desktop has broadband connection. But I do not have any wifi adapter. I want to use my cell phone's wifi adapter and wifi hotspot facility to make internet available for other systems. How can I do that?
It is possible but for that you need to use reverse tethering and then create a wifi hotspot.You can view this XDA thread for more information
PS:- Do you have a laptop? If yes, then you can use wifi hotspot apps to create a hotspot from your laptop