Checking for files to determine if a driver is installed is not a recommended solution.
For example, for the ANT Usb 2 Stick, the only files our old driver installs are the libusb driver files, but since they are the standard libusb files, checking for them does not guarantee that the driver is installed because many devices install and use these files. Even if we do have unique files, such as the new driver which install a unique dll, the presence of the unique file still does not guarantee the drivers are installed because it is possible to uninstall a driver and leave the file present in the system.
A little bit safer option is to read through all the infs in the windows ‘inf’ directory for matching text, but this too is problematic because it is not guaranteed to be compatible with future versions of windows, additionally you would need to search for a match for every version of the inf file. Even if you find the right one, this still doesn’t guarantee the device is using the correct driver, for example it could still be using an older driver version.
The best way to make sure the driver is installed is to use the windows APIs. See this article from Microsoft for instructions
http://msdn.microsoft.com/en-us/library/ff554015(v=VS.85).aspx
Just as reference, here are the driver values you will need for the ANT USB 2 stick (as found in the driver inf file):
ClassGuid = {EB781AAF-9C70-4523-A5DF-642A87ECA567}
HardwareID = USB\\VID_0FCF&PID;_1008
