diff --git a/testsuite/driver/runtests.py b/testsuite/driver/runtests.py
index 52b5471362fd5125d527d49dfbb2ecf6df6b1d3a..103c7ace7c71d4a4a653c6ec7bf2b4086ca75e44 100644
--- a/testsuite/driver/runtests.py
+++ b/testsuite/driver/runtests.py
@@ -143,11 +143,8 @@ if windows:
 # msys gives "MINGW32"
 # msys2 gives "MINGW_NT-6.2"
         config.msys = True
-# msys2 gives 'MSYS_NT-6.3' unless you set MSYSTEM, which is also needed elsewhere
-    elif v.startswith("MSYS"):
-        raise Exception("Remember to set your MSYSTEM environment variable to MINGW32 or MINGW64")
     else:
-        raise Exception("Can't detect Windows terminal type: " + v)
+        raise Exception("Can't detect Windows terminal type")
 
 # Try to use UTF8
 if windows:
diff --git a/testsuite/tests/cabal/ghcpkg05.stderr-mingw32 b/testsuite/tests/cabal/ghcpkg05.stderr-mingw32
index 55a82814deb72473c29d658a3442b0a2e160298d..ac5181679b8373d00f1c733aa09a9a827047817e 100644
--- a/testsuite/tests/cabal/ghcpkg05.stderr-mingw32
+++ b/testsuite/tests/cabal/ghcpkg05.stderr-mingw32
@@ -15,4 +15,4 @@ The following packages are broken, either because they have a problem
 listed above, or because they depend on a broken package.
 testpkg-2.0
 testpkg-3.0
-ghc-pkg.exe: unregistering would break the following packages: testpkg-3.0 (use --force to override)
+ghc-pkg.exe: unregistering testpkg-2.0 would break the following packages: testpkg-3.0 (use --force to override)
diff --git a/testsuite/tests/callarity/perf/all.T b/testsuite/tests/callarity/perf/all.T
index 40b9f01dca6e144d2940d0f0227872ed9936f0a6..1c7969474cef858a9abc9c3424917445ad5d7f35 100644
--- a/testsuite/tests/callarity/perf/all.T
+++ b/testsuite/tests/callarity/perf/all.T
@@ -1,10 +1,9 @@
 test('T3924',
      [stats_num_field('bytes allocated', 
-          [ (wordsize(64), 47080, 5),
+          [ (wordsize(64), 50760, 5),
               # previously, without call-arity: 22326544
               # 2014-01-18: 51480  (amd64/Linux)
               # 2014-07-17: 50760  (amd64/Linux) (Roundabout adjustment)
-              # 2014-09-01: 47080  (amd64/Windows)
             (wordsize(32), 44988, 5) ]),
               # 2014-04-04: 44988  (Windows, 64-bit machine)
       only_ways(['normal'])
diff --git a/testsuite/tests/perf/compiler/all.T b/testsuite/tests/perf/compiler/all.T
index cf6ad8c60de1d07608315e5e3f0fada30f6e7aa7..f53787a7a9e5b0c6144f1388a24fcb4258bf7986 100644
--- a/testsuite/tests/perf/compiler/all.T
+++ b/testsuite/tests/perf/compiler/all.T
@@ -449,9 +449,8 @@ test('T9020',
           [(wordsize(32), 343005716, 10),
            # Original:    381360728
            # 2014-07-31:  343005716 (Windows) (general round of updates)
-           (wordsize(64), 627647808, 10)])
+           (wordsize(64), 728263536, 10)])
            # prev:        795469104
            # 2014-07-17:  728263536 (general round of updates)
-           # 2014-09-01:  627647808 (SPJ compiler improvements)
       ],
       compile,[''])
diff --git a/testsuite/tests/perf/haddock/all.T b/testsuite/tests/perf/haddock/all.T
index 94aef3aac2a2682c31fdc3233703e2901eb7c9cb..ce11f606d86370a3b5d33df7aa21a69abf0c424e 100644
--- a/testsuite/tests/perf/haddock/all.T
+++ b/testsuite/tests/perf/haddock/all.T
@@ -34,7 +34,7 @@ test('haddock.base',
             # 2014-01-22: 62189068 (x86/Linux)
             # 2014-06-29: 58243640 (x86/Linux)
      ,stats_num_field('bytes allocated',
-          [(wordsize(64), 7499083776,  5)
+          [(wordsize(64), 7946284944,  5)
             # 2012-08-14: 5920822352 (amd64/Linux)
             # 2012-09-20: 5829972376 (amd64/Linux)
             # 2012-10-08: 5902601224 (amd64/Linux)
@@ -47,7 +47,6 @@ test('haddock.base',
             # 2014-06-12: 7498123680 (x86_64/Linux)
             # 2014-08-05: 7992757384 (x86_64/Linux - bugfix for #314, Haddock now parses more URLs)
             # 2014-08-08: 7946284944 (x86_64/Linux - Haddock updates to attoparsec-0.12.1.0)
-            # 2014-09-01: 7499083776 (x86_64/Windows)
           ,(platform('i386-unknown-mingw32'), 3548581572, 5)
             # 2013-02-10:                     3358693084 (x86/Windows)
             # 2013-11-13:                     3097751052 (x86/Windows, 64bit machine)
diff --git a/testsuite/tests/perf/should_run/all.T b/testsuite/tests/perf/should_run/all.T
index 457b2ef521be46597390872e3c61db5ec0cc9ba3..1bf0143e03cf783fd1c748d10e83d7ff90709b11 100644
--- a/testsuite/tests/perf/should_run/all.T
+++ b/testsuite/tests/perf/should_run/all.T
@@ -16,11 +16,10 @@ test('T3586',
 
 test('T4830',
      [stats_num_field('bytes allocated',
-          [(wordsize(64), 94496, 1),
+          [(wordsize(64), 98248, 1),
            #             127000 (amd64/Linux)
            # 2013-02-07:  99264 (amd64/Linux)
            # 2014-01-13:  98248 (amd64/Linux) due to #8647
-           # 2014-09-01:  94496 (amd64/Windows)
            (wordsize(32), 70646, 3)]),
            # 2013-02-10:  69744 (x86/Windows)
            # 2013-02-10:  71548 (x86/OSX)
@@ -40,11 +39,10 @@ test('lazy-bs-alloc',
      [stats_num_field('peak_megabytes_allocated', (2, 1)),
                                  # expected value: 2 (amd64/Linux)
       stats_num_field('bytes allocated',
-          [(wordsize(64), 438320, 1),
+          [(wordsize(64), 425400, 1),
             #             489776 (amd64/Linux)
             # 2013-02-07: 429744 (amd64/Linux)
             # 2013-12-12: 425400 (amd64/Linux)
-            # 2014-09-01: 438320 (amd64/Windows)
            (wordsize(32), 411500, 2)]),
             # 2013-02-10: 421296 (x86/Windows)
             # 2013-02-10: 414180 (x86/OSX)
@@ -60,10 +58,9 @@ test('lazy-bs-alloc',
 
 test('T876',
      [stats_num_field('bytes allocated',
-          [(wordsize(64), 72168 , 5),
+          [(wordsize(64), 63216 , 5),
               # 2013-02-14: 1263712 (x86_64/Linux)
               # 2014-02-10:   63216 (x86_64/Linux), call arity analysis
-              # 2014-09-01:   72168 (x86_64/Windows)
            (wordsize(32), 53024, 5) ]),
               # some date:  663712  (Windows, 64-bit machine)
               # 2014-04-04:  56820  (Windows, 64-bit machine)
@@ -95,11 +92,9 @@ test('T3738',
       stats_num_field('bytes allocated',
                       [(wordsize(32), 45648, 5),
                     # expected value: 50520 (x86/Linux)
-                       (wordsize(64), 46840, 5)]),
-                    # 2014-09-01:     46840 (amd64/Windows)
+                       (wordsize(64), 49400, 5)]),
                     # prev:           49400 (amd64/Linux)
                     # 2014-07-17:     50520 (amd64/Linux) general round of updates
-
       only_ways(['normal'])
       ],
      compile_and_run,
@@ -161,10 +156,9 @@ test('T5205',
      [stats_num_field('bytes allocated',
                       [(wordsize(32), 47088, 5),
                     # expected value: 47088 (x86/Darwin)
-                       (wordsize(64), 48920, 5)]),
+                       (wordsize(64), 52600, 5)]),
                     # expected value: 51320 (amd64/Linux)
                     # 2014-07-17:     52600 (amd64/Linux) general round of updates
-                    # 2014-09-01:     48920 (amd64/Windows)
       only_ways(['normal', 'optasm'])
       ],
      compile_and_run,
@@ -275,10 +269,9 @@ test('T7507', omit_ways(['ghci']), compile_and_run, ['-O'])
 
 test('T7436',
      [stats_num_field('max_bytes_used',
-          [(wordsize(64), 58520, 1),
+          [(wordsize(64), 60360, 1),
            #             127000 (amd64/Linux)
            # 2013-02-07:  60360 (amd64/Linux)
-           # 2014-09-01:  58520 (amd64/Windows)
            (wordsize(32), 58434, 1)]),
             # 2013-02-10: 58032 (x86/Windows)
             # 2013-02-10: 58836 (x86/OSX)