There are multiple methods of locating a USB driver for a cell phone, including downloading the driver from the manufacturer's webpage, using Windows Update, or downloading the driver from a third-party webpage. Windows Update automatically attempts to install drivers for a new device connected to a USB port.
Drivers downloaded from Windows Update are certified and approved by Microsoft; however, drivers for many devices aren't available or are outdated. If there's an issue with Windows Update, identify the manufacturer and model of your device, then navigate to the manufacturer's webpage. Look for a link that mentions downloads or drivers. Often, you'll need to navigate to the "Support" section of the site to download drivers. If you're unable to locate driver downloads on the site, look for contact information and request support from the manufacturer.
If you're unable to locate the driver on the manufacturer's page, the driver may be available on a third-party site, such as Download.com or DriverGuide.com. DriverGuide requires you to go through a free registration process before you can download drivers, while Download.com has no registration process. On the download page, verify that the driver is compatible with your operating system, and if the choice for a 32-bit or 64-bit driver is available, ensure you choose the correct one for your computer.