Here’s a (possible) solution.
So you just updated to iOS 5 and you find you have a problem -- you go to use Wi-Fi Personal Hotspot feature and... it's gone?! Don't fret. Stop cursing. It's happened with previous upgrades too. Truth is, It's not really gone, it's just hiding, and here are a couple things you can do to coax it back.
Bug
- Personal Hotspot seems to have disappeared.
Solution 1
Look for it where it lives.- Launch the Settings app.
- Tap General.
- Tap Network.
- Scroll down and look for Personal Hotspot.
- If it somehow got turned off during the update, turn it back on.
- Wait for it to activate.
Solution 2
If that doesn't work, it's time to escalate reset the Settings.- launch the Settings app.
- Tap General.
- Scroll all the way to the bottom.
- Tap Reset Network Settings.