Validity Sensors DDK is an application developed by Validity Sensors, that allows you to check and verify user identity through biometric fingerprinting tools. Since your computer has a fingerprint reader and the Validity Sensors DDK doesn't occupy much space, I recommend you keep the program. If you're using a password logon instead of a fingerprint logon, you can safely uninstall the application using the Add or Remove Programs feature:
If you use Windows XP or below you can go to Start > Control Panel > Add or Remove Programs. In the Currently installed programs box, click on the Validity Sensors DDK program and then click Remove.
If you have Windows Vista or above, you need to go to Start > Control Panel > Programs > Programs and Features. Select the Validity Sensors DDK application and click Uninstall.