I also faced the same problem and tried almost everything possible from manually installing drivers to editing the winusb.inf file. But nothing worked for me.
Actually, the solution is quite simple. Its always there but we tend to miss it.
Prerequisites
Download the latest Android SDK and the latest drivers from here. Enable USB debugging and open Device Manager and keep it opened.
Steps
1) Connect your device and see if it is detected under "Android Devices" section. If it does, then its OK, otherwise, check the "Other devices" section and install the driver manually.
2) Be sure to check "Android Composite ADB Interface". This is the interface Android needs for ADB to work.
3) Go to "[SDK]/platform-tools", Shift-click there and open Command Prompt and type "adb devices" and see if your device is listed there with an unique ID.
4) If yes, then ADB have been successfully detected at this point. Next, write "adb reboot bootloader" to open the bootloader. At this point check Device Manager under "Android Devices", you will find "Android Bootlaoder Interface". Its not much important to us actually.
5) Next, using the volume down keys, move to "Recovery Mode".
6) THIS IS IMPORTANT - At this point, check the Device Manger under "Android Devices". If you do not see anything under this section or this section at all, then we need to manually install it.
7) Check the "Other devices" section and find your device listed there. Right click -> Update drivers -"Browse my computer..." -> "Let me pick from a list..." and select "ADB Composite Interface".
8) Now you can see your device listed under "Android Devices" even inside the Recovery.
9) Write "adb devices" at this point and you will see your device listed with the same ID.
10) Now, just write "adb sideload [update].zip" and your are done.
Hope this helps.