Welcome to fido Technical community,
Can you please elaborate what your trying to sync exactly using the Windows 7?
Please also remember you can only sync one computer at all times for music,apps and pictures. When you try to sync multiple computer for these sync Items (it wipes the phone content and overwrites the sync items to match the computer content)
Please try the following on windows 7.
When you plug the device and you click on Computer
Under Portable devices you will see Your Iphone. If you don't see Your Iphone please refer to this link
I hope this helps,