Q: Why my iPhone 3GS ask me to restore after up grading to iOS6.1??? and cannot restore till now. How can I do it?

I tried to upgrade my iPhone 3GS when I saw a notification at my iTune " your devise can upgrade to iOS6.1.1. So I upgrate through my computer on iTune. After one hour one message pop up " there is problem ocure why upgrading and asked me to restore" So I did it and afew minutes later iPhone screen pop up and ask me to restore. I follow instruction but cannot restored and on my iTund said your iPhone is not install SIM and unplug and install it. I try but same problem repeating. Please help me. I have alot of information in my phone and now I cannot check my contact list and notes.

Please help me