MS keyboard behaves strangely

[OCOC]

I have MS natural keyboard pro. When i press left *alt* key, sound volume goes down and my Volume+/- doesn't work either. I uninstalled and reinstalled intellitype 5.5 but nothing works.

have any ideas how to fix this problem.?

thank you

[redduc900]

Check your settings here... Control Panel | Regional Language Options | "Languages" tab | "Details" button | "Settings" tab | Installed services --> Keyboard.

[OCOC]

Check your settings here... Control Panel | Regional Language Options | "Languages" tab | "Details" button | "Settings" tab | Installed services --> Keyboard.
Under "Keyboard", US is listed.

all my keyboard hotkeys really mess up. When I press mute, volume is off and IE browser open.