Can't update to newest android and system version

System Version: 2.3
Android: 2.2

I have a moto droid global 2. The reason why my firmware is outdated is because I can't update. I would like to update it. I was to lazy to post this question earlier, but now I'm posting it :). I can download the updates but can't install it. After I download and press install, my phone does something, than restarts and says unable to update or something like that. If you need a more thorough explanation please let me know so I can try it again. I've tried installing it and downloading it like 5 times. Please help me and thank you for your help in case I don't get back to you in time.