Do you really want to have your drivers dependent upon
having the .NET framework installed?

C# uses the .NET framework. The .NET framework, as it currently is, is
simply unusable in kernel mode, which is where device drivers reside. The
exception is the new user-mode driver framework (from Windows XP SP2
upwards), but even that would just mean a lot of P/Invoking in C#. C# would
make your job harder here, not easier.

For now, device driver development is still restricted to C/C++. It's an
advanced topic with a high learning curve if you're only used to user-mode
programs, so make sure you know what you're getting in to. Depending on the
kind of device, you may not have to write a driver, but just a program that
can communicate with the device over an existing bus (parallel port, USB,
serial, whatever). If your device has only one specialized function and
doesn't require microsecond-precision timing, having a program to control it
may be as good as having a general-purpose driver.

Virtually 99% of driver development for the Windows OS must be done with C++,
because of the fact that drivers require native code that interacts directly
with the OS.
-- Peter
Site: http://www.eggheadcafe.com
UnBlog: http://petesbloggerama.blogspot.com
MetaFinder: http://www.blogmetafinder.com 

Nonwithstanding the other replies here, it really depends on what you
actually mean by "driver".

One such topic I've seen was the request for a driver, when the end
result was that this was a proprietary device, built for one specific
software application, and it used usb, so the programmer could talk to
it using the usb api without actually building a proper driver for it.
If this is true also for your device, you could get by without actually
creating a "driver".

But as the others have said, C# can't make real drivers.