The latest version 4.1 of TESSY (64Bit) fully supports C/C++ and contains many new functions compared to TESSY 4.0: With an automated Fault Injection a special test code can be instrumented into the source files to be tested. The new script perspective allows textual editing of tests in a dedicated test scripting language. The integrated Classification Tree Editor (CTE) has been implemented as a full Eclipse-based editor and enhances the design of test cases and the assignment of test data to tree nodes. As a dynamic test tool, TESSY 4.1 includes a static code analysis: Calculation of the cyclomatic complexity (McCabe metric) as well as further derived test case quality measures. The Test Data Editor (TDE) now provides the possibility of entering arithmetic expressions as test data. To stimulate or measure hardware signals during the test, TESSY V4.1 provides a hardware adapter interface that can be used to control external hardware for stimulation and measurement of hardware signals. Also, the existing support of TESSY for the compilers of Wind River has been extended to this new TESSY 4.1 version.