The iOS on my iPhones 4S is current, and I have a PC with Windows 7. Processor is the Intel i7 and I have 12GB of RAM, so I doubt it's a hardware issue. This started happening several weeks ago, so maybe some Windows update is causing issues? Workaround is to open Task Manager to force close iTunes and restart. Seems to happen 30%-50% of the time. I'm not able to troubleshoot the cause. Any ideas?