Here we'll review the bare minimum to get a system up and running.
Pick a location for ScanImage Installations, hereafter referred to as <ScanImage>
C:\My Documents\Matlab\ScanImage\<scanimage version> C:\Program Files\ScanImage\<scanimage version>
ScanImage requires write permissions to its installation folder. In Windows 7 and later, users do not have write permissions for the folder C:\Program Files by default. If this folder is chosen for the ScanImage installation, modify the Windows Folder Permissions of the ScanImage installation folder appropriately.
Download ScanImage and extract the ZIP file into selected folder
Launch Matlab and add the folder to the search path (Tip: It is sufficient to use the option 'Add Folder...' - On startup, ScanImage will add additional folder to the path