Many phones can connect to your computer via USB for transferring files such as music and pictures. In addition to regular transfers, some phones including the iPhone use a computer program to transfer sync data and install apps. If you know your phone supports a computer connection but your computer won't detect the phone, you may need to change the settings on your phone, install the correct drivers on your computer or install special software.

Connecting an iPhone

To transfer most types of files to and from an iPhone, you need iTunes installed on your computer. Installing iTunes also installs the driver required for your computer to recognize the phone. Download and install iTunes from Apple's website (see Resources) before plugging your phone in. If your iPhone stops connecting after an iOS, iTunes or computer update, try uninstalling iTunes and reinstalling it. Apple also notes that some third-party software, including many cellular device connectivity programs, can interfere with the iPhone. Uninstall any such programs, reinstall iTunes and try again.

Transferring to Android

Android phones do not require special drivers for file transfers when used with Windows 7 or 8. In the Settings app, open "Storage," press the menu button and tap "USB computer connection." Turn on "Media device" mode to connect your phone and enable transfers. You can also turn on "USB debugging" in the Developer Options to access your phone via command line, but this method may require drivers from your phone manufacturer. If you use a Mac, download the Android File Transfer program (see Resources) to connect your phone to your computer. Some Android phones vary slightly, so check your phone's manual if these directions do not apply to your model.

Regular Phones

Non-smartphones use a variety of methods to connect to computers. Some appear as media devices, like Android phones, while other require drivers or software from the phone manufacturer. If your computer does not automatically detect your phone when you connect it, check the manufacturer's website for drivers or software for file transfer. Your phone may also have included a CD with the necessary drivers. Some phones only support file transfers over Bluetooth, even though they can connect via USB for other functions.

Hardware Causes

Aside from software issues, your phone may not appear on your computer due to hardware problems. A faulty USB cord or a damaged USB port on either the phone or your computer will prevent the phone from showing up. If possible, try using a different cord or connecting the phone to another computer to help troubleshoot the problem. If no other solutions work, your phone may have an internal hardware problem.