TWAIN is the de facto interface standard for scanners. Nearly all scanners come with a TWAIN driver, which makes them compatible with any TWAIN-supporting software. The word TWAIN comes from Rudyard Kipling's The Ballad of East and West which reads, "East is East and West is West, and never the twain shall meet." The TWAIN driver itself is simply the software provided by the scanner's manufacturer to operate the scanner.
Close all running applications. Go to the folder where you have the TWAIN driver. Double-click "Setup.exe." The Confirm File Deletion window will appear. The TWAIN driver is going to delete previous versions of itself before installing the current version. A "ReadOnly File Detected" window may appear several times.
Click "Yes" each time the "ReadOnly File Detected" window appears. TWAIN is either trying to delete or change files on the hard drive that cannot be accessed except for "read-only" purposes.
Click "Finish" when the Maintenance Complete window appears.
Double click "Setup.exe" again. Now the TWAIN driver will install. The "Welcome to the Installshield Wizard for TWAIN Data Source" window appears.
Click "Next." The License Agreement opens.
Click "Yes." The Driver Preference window appears. Select personal preferences such as paper size and unit of measure. Click "Next." The InstallShield Wizard is Complete window opens.
Click "Finish" to complete installation of the TWAIN driver.