scanner HELP HELP HELP!!!!!!!!!!!!!!!!!

i have a acer prisa flatbed scanner and when i try to install it with the add new haredware wizard it tell me that this device is already installed but has a problem so when i view the properties and it say the drivers for this device is not installed (code 28) i have try to restalled the driver i have done a format and recover and i have juet done a recover on my computer please help