sentences:  This check came to be known as the AARD code.It was a simple matter for Digital Research to patch DR DOS 6.0 to circumvent the AARD code 'authenticity check' in the Windows 3.1 beta by rearranging the order of two internal tables in memory (with no changes in functionality), and the patched version, named "business update", was on the streets within six weeks of the release of Windows 3.1.With the detection code disabled, Windows ran perfectly under DR DOS and its successor Novell DOS.