How To Fix "No SIM Card Installed" Error On iPhone 4S

With the public release of iOS 5.0.1, many users faced this problem which is "No Sim Card Installed" and specially for iPhone 4S users, so what should you do ?! Well a new Apple support document the updated build designed to solve SIM card-related errors.

From Apple support documents: 

In certain situations, iPhone 4S may have difficulty recognizing a micro-SIM card, resulting in the following behaviors:
“Invalid SIM” or “No SIM Card installed” alert appears intermittently.
Status bar displays “No Service” or “Searching” in a location with good network coverage.

So simply you are going to follow this easy steps that has been already tested and will fix No SIM card installed error, let's see how it works:

STEP 1: Back up your user content and settings using iTunes or iCloud.
STEP 2: Now restore your iPhone 4S using iTunes.
STEP 3: After the process is complete, restore your user content and settings from your backup.

STEP 4: Finally, confirm that you’ve successfully restored, verify that the version is now iOS 5.0.1 (9A406) in Settings > General > About.

That's it you are done, and this error is fixed, I hope you made it in a correctly way....