How Do I Unlock a Disabled iPod Touch From a Different Computer?
When you initially configure your iPod Touch, the computer used for setup becomes the iPod's "home." When connecting to a different computer to add music and media, the iPod will have to be re-synced with that computer -- erasing all content. This becomes an even bigger obstacle if the iPod Touch has a pass code, disabling use of the device until it is unlocked. You can get around this lockout and use the device with a new computer by restoring the iPod to its factory settings, effectively erasing all data on the iPod.
Connect the locked iPod Touch to the new computer via USB cable.
Select the iPod Touch in the iTunes sidebar, select the "Summary" tab.
Click "Restore." A warning dialog will display, informing you that this will erase the entire contents of the iPod. Confirm the action. iTunes will begin erasing the iPod Touch. The device will restart several times during the process.
Select "Set up as a new iPod Touch" when the device reappears in the iTunes sidebar, after the restore completes. Do not restore from a backup. Follow the on-screen instructions to configure the iPod Touch. Once finished, the lock is removed and the device can be used and synced with the new computer.