Resolving the problem where all your iPhone Apps cannot be launched

Just recently I helped someone resolve a weird problem on the iPhone. It seems that all the iPhone apps cannot be launched except for those apps that comes with the iPhone (e.g. Contacts, Weather). I did a little digging and it seems to be due to a syncing problem.

To resolve it, just do the following:

1. Ensure that your iPhone is not plugged in
2. Launch iTunes on your computer
3. Click on Store > Deauthorize Computer (follow the instructions)
4. Quit iTunes and relaunch it (may be optional)
5. Click on Store > Authorize Computer (follow the instructions)
6. Plug in your iPhone and do a sync

That's it. After this, all your apps will work. Apparently from what I understand, the iTunes software somehow indicated to your iPhone that all the apps are unauthorised which is why you're unable to launch your downloaded apps. Doing the above steps will help "reset" the iPhone authorisation.

Hope this helps...