This post details how I resolved the frustrating ”Searching Phone” and “Unable to detect your phone” error messages when connecting a Sony Xperia S smartphone to a Windows 7 PC via USB.
1. Disconnect the Sony Xperia S from the PC.
2. Turn off USB debugging if it’s enabled:
Menu > Settings > Applications > Development > USB debugging
3. Clear data for the MTPapp in the phone.
Menu > Settings > Applications > Manage applications > All > Mtpapp
Try connecting my Sony Xperia S to the PC again now. If you’re lucky, PC Companion will now successfully detect your phone. If problems persist, these further steps can help resolve the problem:
4. Connect the phone via USB and go to the Device manager on the computer. Check if you can locate the phone or any Unknown/New device that could be the phone or if you perhaps see the phone as a device. Right click it and select to uninstall.
5. Still in Device manager open the list for USB controllers (Universal Serial Bus Controllers) and right click each one of these controllers and select to uninstall.
When all of this is done reboot your computer and before connecting your phone again repeat step 2.
You should of course not have to do this every time you connect your phone to your computer but hopefully this could remove any error causing your phone not to connect properly.