Iphone 3GS 4.3.4 BB 6.15.00 To Downgrade??????
 

I have iphone 3GS ios 4.3.4 BB 6.15.00 I want to downgrade my baseband

Is there any possibility

Also I tried to downgrade IOS 4.3.4 to 4.3.3 with the given method below but there comes error

• For Windows Locate the path as follows: – “C:\Windows\System32\drivers\etc\” and locate its file as hosts.
• For Mac users can access the “hosts” file by navigating to “/etc/” folder, which can be found through Go > Go to Folder from within Finder
• Open it in Notepad (for Windows) or TextEdit (for Mac OS X) and add this at the bottom of the file and write the following line at the end of it 74.208.105.171 gs.apple.com and then save it.