We keep reminding the iPhone users that the update of the iTunes software is extremely important. If the program is not up to date, there is a bigger chance you will get the error. If you are a Mac user, open the program, choose iTunes from the Menu and click on the Check for Updates. If you are a Windows user, click on Help, and Check for Updates.
Another reason why error 2 is there may be in the wrong time, date and time zone data. Check them on your computer, and if you see some irregularities, correct them.
Open the Internet Explorer. Click on the Tools Menu, and choose Internet Options. Click on the Advanced. Look for Use TLS 1.0 and USE SSL 3.0 in the security section. One or both boxes should be selected. If they are not, you can select them both. Once you do that, click on OK.
For some users, simple computer restart was helpful, and the error disappeared. Do the same, and open iTunes again. Try to restore or update.
Security software is one of the reasons why the error 2 occurs. First, check if your software is up to date, and if not, update it. The second solution is to turn it off until you are finished with the task. The option number three is to uninstall the software from your computer.