diff --git a/collects/deinprogramm/deinprogramm-langs.rkt b/collects/deinprogramm/deinprogramm-langs.rkt
index bde5c922e7..20dd4b8de6 100644
--- a/collects/deinprogramm/deinprogramm-langs.rkt
+++ b/collects/deinprogramm/deinprogramm-langs.rkt
@@ -170,7 +170,8 @@
                   [scheme-test-module-name
                    ((current-module-name-resolver) '(lib "test-engine/scheme-tests.rkt") #f #f)]
                   [scheme-signature-module-name
-                   ((current-module-name-resolver) '(lib "deinprogramm/signature/signature-german.rkt") #f #f)])
+                   ((current-module-name-resolver) '(lib "deinprogramm/signature/signature-german.rkt") #f #f)]
+                  [tests-on? (preferences:get 'test-engine:enable?)])
               (run-in-user-thread
                (lambda ()
 		 (when (getenv "PLTDRHTDPNOCOMPILED") (use-compiled-file-paths '()))
@@ -201,7 +202,7 @@
 			   (send (send engine get-info) signature-failed
 				 obj signature message blame))))))
                  (scheme-test-data (list (drscheme:rep:current-rep) drs-eventspace test-display%))
-                 (test-execute (get-preference 'tests:enable? (lambda () #t)))
+                 (test-execute tests-on?)
 		 (signature-checking-enabled? (preferences:get 'signatures:enable-checking?))
                  (test-format (make-formatter (lambda (v o)
 						(render-value/format (if (procedure? v)
diff --git a/collects/lang/htdp-langs.rkt b/collects/lang/htdp-langs.rkt
index 158d6fb94a..d99c89ef9f 100644
--- a/collects/lang/htdp-langs.rkt
+++ b/collects/lang/htdp-langs.rkt
@@ -143,7 +143,8 @@
                   [scheme-test-module-name
                    ((current-module-name-resolver) '(lib "test-engine/scheme-tests.ss") #f #f)]
                   [scheme-signature-module-name
-                   ((current-module-name-resolver) '(lib "deinprogramm/signature/signature-english.rkt") #f #f)])
+                   ((current-module-name-resolver) '(lib "deinprogramm/signature/signature-english.rkt") #f #f)]
+                  [tests-on? (preferences:get 'test-engine:enable?)])
               (run-in-user-thread
                (lambda ()
                  (when (getenv "PLTDRHTDPNOCOMPILED") (use-compiled-file-paths '()))
@@ -171,7 +172,7 @@
                             (send (send engine get-info) signature-failed
                                   obj signature message blame))))))
                  (scheme-test-data (list (drscheme:rep:current-rep) drs-eventspace test-display%))
-                 (test-execute (get-preference 'tests:enable? (lambda () #t)))
+                 (test-execute tests-on?)
 		 (signature-checking-enabled? (get-preference 'signatures:enable-checking? (lambda () #t)))
                  (test-format (make-formatter (lambda (v o) (render-value/format v settings o 40)))))))
             (super on-execute settings run-in-user-thread)
diff --git a/collects/test-engine/test-tool.scm b/collects/test-engine/test-tool.scm
index ee89f12669..635d701ee7 100644
--- a/collects/test-engine/test-tool.scm
+++ b/collects/test-engine/test-tool.scm
@@ -181,7 +181,7 @@
                           (when enabled?
                             (set! enabled? #f)
                             (send this set-label enable-label)
-                            (preferences:set 'test-engine:enable? #t)))
+                            (preferences:set 'test-engine:enable? #f)))
                         (super-instantiate ()))]
                      [enable? (preferences:get 'test-engine:enable?)]
                      [enable-menu-item (make-object enable-menu-item%
diff --git a/collects/tests/drracket/test-engine-test.rkt b/collects/tests/drracket/test-engine-test.rkt
index fc8edf0168..8cdadf30e7 100644
--- a/collects/tests/drracket/test-engine-test.rkt
+++ b/collects/tests/drracket/test-engine-test.rkt
@@ -39,11 +39,11 @@
 		   (list (make-signature-violation "\"bar\"" 1 7)))
   (test-expression "(: foo (Integer -> Integer)) (define (foo x) x) (foo \"foo\")"
 		   "\"foo\""
-		   #:repl-expected "foo: this name was defined previously and cannot be re-defined\n\"foo\""
+		   #:repl-expected "foo: this name was defined previously and cannot be re-defined\n"
 		   #:signature-violations-expected
 		   (list (make-signature-violation "\"foo\" at line 1, column 48 " 1 8))
 		   #:repl-signature-violations-expected
-		   (list (make-signature-violation "\"foo\" at line 4, column 50 " 1 8)))
+                   (list))
   (test-expression "(: foo (Integer -> Integer)) (define foo (lambda (x) x))"
 		   ""
 		   #:repl-expression "(foo \"foo\")"
@@ -62,11 +62,11 @@
 		   (list (make-signature-violation "\"bar\"" 1 7)))
   (test-expression "(: foo (integer -> integer)) (define foo (lambda (x) x)) (foo \"foo\")"
 		   "\"foo\""
-		   #:repl-expected "define: Zweite Definition für denselben Namen\n\"foo\""
+                   #:repl-expected "define: Zweite Definition für denselben Namen"
 		   #:signature-violations-expected
 		   (list (make-signature-violation "\"foo\" at line 1, column 57 " 1 8))
 		   #:repl-signature-violations-expected
-		   (list (make-signature-violation "\"foo\" at line 4, column 59 " 1 8)))
+		   (list))
   (test-expression "(: foo (integer -> integer)) (define foo (lambda (x) x))"
 		   ""
 		   #:repl-expression "(foo \"foo\")"
@@ -459,8 +459,21 @@
     (check-failures (append signature-violations-expected repl-signature-violations-expected)
 		    (append check-failures-expected repl-check-failures-expected))))
 
-
-
+(define (test-disabling-tests)
+  (define drs (wait-for-drscheme-frame))
+  
+  (parameterize ([language (list "How to Design Programs" #rx"Beginning Student(;|$)")]) 
+    (prepare-for-test-expression)
+    (test:menu-select "Racket" "Disable Tests")
+    (test-expression "(check-expect 1 2)" "Tests disabled.")
+    (test:menu-select "Racket" "Enable Tests"))
+  
+  (parameterize ([language (list "DeinProgramm" #rx"Die Macht der Abstraktion - Anfänger(;|$)")])
+    (prepare-for-test-expression)
+    (test:menu-select "Racket" "Disable Tests")
+    (test-expression "(check-expect 1 2)" "Tests disabled.")
+    (test:menu-select "Racket" "Enable Tests")))
+  
 (define-syntax (go stx)
   (syntax-case stx ()
     [(_ arg)
@@ -479,6 +492,7 @@
   (go DMdA-beginner)
   (go DMdA-vanilla)
   (go DMdA-assignments)
-  (go DMdA-advanced))
+  (go DMdA-advanced)
+  (go test-disabling-tests))
 
 (fire-up-drscheme-and-run-tests run-test)
diff --git a/collects/unstable/gui/language-level.rkt b/collects/unstable/gui/language-level.rkt
index 6f58381867..8eed798e04 100644
--- a/collects/unstable/gui/language-level.rkt
+++ b/collects/unstable/gui/language-level.rkt
@@ -6,6 +6,7 @@
          racket/gui/base
          drracket/tool
          string-constants
+         framework/preferences
          (only-in test-engine/scheme-gui make-formatter)
          (only-in test-engine/scheme-tests
                   scheme-test-data test-format test-execute)
@@ -151,7 +152,8 @@
         (let* ([drracket-namespace (current-namespace)]
                [test-engine-path
                 ((current-module-name-resolver)
-                 'test-engine/scheme-tests #f #f)])
+                 'test-engine/scheme-tests #f #f)]
+               [tests-on? (preferences:get 'test-engine:enable?)])
           (run-in-user-thread
            (lambda ()
              (namespace-attach-module drracket-namespace test-engine-path)
@@ -160,7 +162,7 @@
               (list (drracket:rep:current-rep)
                     drracket-eventspace
                     test-display%))
-             (test-execute (get-preference 'tests:enable? (lambda () #t)))
+             (test-execute tests-on?)
              (test-format
               (make-formatter
                (lambda (v o) (render-value/format v settings o 40))))))