Carefully inspect the box your iPhone. If you have an earlier version, then it can be glued sticker, which contains the firmware version of the device. Otherwise, you must first activate the phone through iTunes before you can determine the version.
Look on the home screen of the iPhone Settings menu ("Settings"). Go to the tab General ("Core") and then select About section ("About phone"). There will be presents all information about the device. Scroll through the text until, until you see the serial number and the version of the iPhone. For example, maybe the inscription 4.2.1 (8С148). Write down this information on a separate sheet, to further it was possible to reflash the device.
Turn on your iPhone and navigate to the keyboard via the function of the Slide for emergency. Dial *3001#12345#* and press call button. A menu will appear overhead - scroll down and find the section Versions. Rewrite the data specified by referring to the Fireware version. It is possible to determine the version of the firmware. If it says 04.26.08_G, then this corresponds to version 3.0, and for the label 04.05.04_G - iPhone version 2.0. The compliance information can be found on many Internet sites dedicated to the iPhone.
Find the serial number on the box next to the caption Serial No. Also, this information can be found on the phone under the battery. Find 4 or 5 digit serial number which indicates the week of manufacture of your device. Depending on this, you can determine the version of the firmware.
To do this, find the Internet a special table. For example, if the number is less than 38, it corresponds to version 1.0.2. This method not always can be used to determine the version, as it is imprecise and requires confirmation by other methods.