3gs untethered problem

[kameshmanwani]

I have jailbreaked and unlocked my iphone 3gs 4.2.1 with redsn0w_win_0.9.6b5. After the jailbreak i got the baseband 6.15.00. It is a tethered jailbreak, is there a possible way now to convert it into a Untethered jailbreak with unlock?
I do not want to reboot my phone with conecting it to redsn0w_win_0.9.6b5 every time, so i want my phone to get it untethered. Please help, I am in a big problem because of this situation.
Is there a way to make restore my phone into a normal position that is without jailbreak and unlock, please help
I just want to reboot my iphone properly again, even if i have to lose my unlock and jailbreak..please help
Thanks in advance

[Simon]

Yes, use greenpoison rc6.1 on it. That will untether it.

Greenpois0n.com

[kameshmanwani]

will the phone still be carrier unlocked????

[Simon]

Yes

[kameshmanwani]

I tried the greenpois0n 4.2.1 , but nothing happened. I got the error message-
No succesfull from the download 60000 ms!...
What do I do now?

[Simon]

Try it again, it can take a second time to work.

[kameshmanwani]

can i restore it to a custom firmware 4.2.1 and then greenpoison rc6.1 it and then use Ultrasn0w 1.2 to unlock it so that the iphone will be untethered and carrier unlocked???
If any of the 3 steps is wrong please inform me....
Thanks in Advance...