iTunes does not connect to my iPhone

Does anyone else have a probelm with iTunes not detecting their iPhone - either through wi-fi connection or when connected through a USB cable? My computer currently uses Windows 7 and I have had SERIOUS issues with the USB ports - which is why I think iTunes doesn't acknowledge my phone when it's plugged in - heck, my computer doesn't even acknowledge my phone.

I've tried connecting my iPhone to my computer through my wi-fi network but although the phone shows up in the control panel, it isn't fully functional - declares it requires "troubleshooting"; all the while, my phone continues to try to connect to my computer, but never does. This goes on for about 10 minutes then I get a message on my phone "Software Update Failed An error occurred downloading iOS5.1." Then i can either click "close" or "settings".

So, I can't update to iOS 5.1 because I can't get my computer to connect with my phone. This is probably a Microsoft or windows problem, but thought I would ask in case anyone else has the same factors and issues.

Thanks!