Software that has been successfully operated on previous versions of Windows will not necessarily work automatically with the current version of the operating system. Possible reasons for this may include new security features or operating system properties, as well as the discontinuation of functions or services. As a result, the use of certain software may be limited or impossible. In new Windows versions, activating new security features (for example) may result in compatibility issues. Examples of this include User Account Control (UAC), or Kernel Patch Guard in 64-bit versions of the operating system. In addition, signed drivers may be necessary, but not available for older devices. Functions are also regularly omitted from newer versions of Windows. One example involves the discontinuation of the GINA login component, which was used by several fingerprint readers.