If you didn't install ADB driver or even never heard about it, you need to go through this page carefully. If you have installed ADB driver and ensure ADB works, please ignore this page and go to next step.
Download ADB driver:
You can go to Google website for that: http://developer.android.com/sdk/win-usb.html. It might be a little troublesome since your need to install Android SDK first. For your convenience, you can download the driver package and adb utility directly.
Steps to install ADB driver:
1. Connect your phone to PC
2. Go to Settings-> Applications->Development. Disable and enable USB Debugging. You must NOT turn on USB storage.
3. Windows will report new hardware is found. Select "Install from a list or specific location (Advanced)" and click Next
4. Select "Search for the best driver in these locations" and "Include this location in the search". And set the path to the folder of ADBdriver you just downloaded and unzipped. Click Next
5. Wait for some time and the wizard will finish
Verify that ADB driver was installed correctly:
If your phone is listed, Congratulations! Now you can go to next step!