iphone 4 04.12.01 unlockable? Also how to know if it is jailbreaken

I am new to iphone and am totally lost with this one.

1. Is there as simple way to know if my iphone is jail broken or not? I used redsn0w and it did say process complete but then my xp got blue screen. My iphone was on easily with no problem and I can see cydia. But clicking it don't open anything..just screen flash and thats it. I saw contents of my iphone with ifunbox and saw cydia folder. Does it mean anything about the jailbreaking status of my iphone?

2. Is it true that my iphone couldnt be unlocked at all currently? It is running OS 5.1 on basebad 04.12.01. Is there any tool that can do the job? I read a lot about the baseband been the problem. Could it be changed like upgraded or downgranded then unlock itt?

 

in my opinion, your jailbreak may not fully complete. I suggest restoring and jaibreak again just to be sure. As for unlocking your iphone, i have the same phone,vesion and baseband and can cannot find a way to unlock so if you do fina way please let me know.