Dimsntfy.dll is a file used by Windows to handle the logging-on and logging-off procedure operated by Windows. Basically, your computer needs it every time you log in and log out of your account. It is associated with Microsoft’s “credential roaming module”. This part of the system handles encrypted data, such as passwords or authenticating identity. It is a file that is widely used on most Windows versions, including Microsoft Windows XP, Windows 7, and 2003. Although it’s vital for the smooth operation of your system, it’s continually causing problems with your PC. If you have problems with this file, you should resolve it with the tutorial on this page.