Hi,
What is the make and model number of the scanner?
Follow these steps mentioned below and check.
a. Click on Start button.
b. Open Control Panel , type Devices and Printers in the search box.
c. Right click the scanner icon scanner and select Create Shortcut.
d. The shortcut for the scanner will be placed on the Desktop.
Reference -
http://windows.microsoft.com/en-US/windows-vista/Scan-a-document-or-file
http://office.microsoft.com/en-us/word-help/scan-and-edit-a-document-HA010254879.aspx