Hey all. I have an ipad with version 3.2.2 installed and wanted to update to version 4.2.1. When I plug the ipad into the computer, itunes pops up asking if I want to do the update. I accept, and it seems to start but then bump into an error with code -23

I went to the apple website to look for such an error code but can't find it anywhere. Any help? Thanks.
make sure you have the latest itunes. in addition sometimes itunes conflicts the usb drivers you would then need to reboot or use another usb port or another machine...
Error 23, 28, 29, 40, 1002, 1011, 1012, 1014, 1611: These errors may indicate a hardware issue with your device. Follow the steps and also attempt to restore while connected with a known-good 30-pin Dock Connector cable, computer, and network to isolate this issue to the device. If the MAC address is missing or the IMEI is the default value (00 499901 064000 0), this can also confirm a hardware issue.

Try these Resolutions:

1) Update to the latest version of iTunes
* Windows: Choose Help > Check for Updates
* Mac: Choose iTunes > Check for Updates

2) Make sure that your operating system is up-to-date with the latest software updates.

On a Mac, choose Software Update > from the Apple () menu and install all available updates. If an update requires a restart, check for updates again after the restart.

On a Windows PC, to get the latest updates, go to the Microsoft Windows Update page. If an update requires a restart, check for updates again after the restart.

3) Restart your computer

Simply restarting the computer can clear up certain issues that could prevent you from restoring iPhone, iPad, or iPod touch. After you restart, try restoring the device again in iTunes.

4) Open the proper ports and allow access to Apple servers

During the update and restore process, iTunes needs to contact Apple. Ensure that your computer has the following ports open and can access these servers:

* Port 80
* Port 443
* phobos.apple.com, albert.apple.com, gs.apple.com

5) Restore on a different computer

If the issue is not resolved with the above steps, try to restore using a different computer. Ensure that the computer you use has USB 2.0 ports, the latest version of iTunes, and that you connect directly to the computer.

If another computer is not available, proceed to the Advanced Steps below.

6) Advanced Steps
To perform some of the steps in this article you need to be logged in as an administrator on the computer. If you need to review the steps to restore, refer to http://support.apple.com/kb/HT1414

7) If you have performed all of the steps and you are still experiencing a restore/update issue, contact Apple
lol wouldnt it be easier for u to just post the link m0ei? :P

I did see that page but still I am having the problem with the latest itunes version 10.1.2 and with several computers. I did try on both mac and windows, but still the same error occurs. I tried also on another ipad, and still same problem!

I did check the gateway server, and the necessary links can be accessed normally. This is very weird :S