press ‘g’ key and window pops up – why?

I cant understand why everytime I press the “g” key on my keyboard (doesnt matter what program i am working in) a window that looks like “My Computer” screen pops up. The screen looks similiar to the Windows Explorer screen where you can see all the drives and such. The keyboard is not wireless and it has no short cut keys (very basic). What kind of macro or such is presenting me with this nusiance application. All help would be appreciated. Using Windows XP.
Thanks.