Is it not showing in device manager or is it that you just don't know how to use it? If it's seen by the system any program that uses the webcam will use it, Skype for example.
What do you mean as "Activate"? Usually, IP webcams (if this is what you got) have an installation CD which you run on Windows PC, and then configure your webcam. First configuration is usually done with wired connection to the webcam.
Is it not showing in device manager or is it that you just don't know how to use it? If it's seen by the system any program that uses the webcam will use it, Skype for example.