Visual C#: To check a hardware had connected to PC

I'm newbie of Visual C#.

I need to modify a pc based application which developed by Visual C# 2010. There is a button to open a "Chinese Handwriting Recognition System" software.

But I want to add a checking that the USB handwriting Pad had not connected to the PC or not. If not, it will prompt a message to remind to attached the USB pad.

How can I check the hardware had开发者_开发百科 connected to PC or not ?

Thanks. Joe

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I think you are looking for this;

How do I check whether a given USB device is plugged in? Or possibly this might do what you need as well;

C# Checking for presence of usb drive