Really need help

[Regeono]

I can't open any programs like Microsoft work or almost any and my audio service isn't running... it's all gone to hell.. When I try to open most applications I get an error Windows cannot access the specified device, path, or file. You may not have the appropriate permissions to access the item.

I really need help fast. I HAVE VISTA

[Greg]

Is the hard drive failing? Was the password hacked and encrypted files damaged?