Manual Update

How to Manually Update iOS 4.0

for windows:

1. Connect iPhone/iPod Touch to PC
2. Now once iTunes starts click on your iPhone/iPod Touch from devices list
3.  Hold shift key and click on Update button
4. Now browse & select downloaded iOS 4.0 firmware  and click on Open

5. Let iTunes do the rest of job for you.

For Mac OS X:

1. Connect iPhone/iPod Touch to PC
2. Now once iTunes starts click on your iPhone/iPod Touch from devices list.
3. Hold Option key and click on Update button
4. Now browse & select downloaded iOS 4.0 firmware and click on Open
5. Let iTunes do the rest of job for you.
It may take some time for iTunes to complete updates, don’t remove your iPhone/iPod Touch until iTunes has complete its task. Now enjoy iOS 4.0 on your iPhone/iPod Touch.