diff --git a/RELEASE_NOTES.md b/RELEASE_NOTES.md
index c81a24e50c4..4063e57f5d7 100644
--- a/RELEASE_NOTES.md
+++ b/RELEASE_NOTES.md
@@ -179,6 +179,9 @@
 * Fix NuGet key leak if push fails (https://github.com/matthid/FAKE/pull/2)
 * Coreclr nunit3 params (https://github.com/matthid/FAKE/pull/3)
 
+#### 4.64.6 - 21.02.2018
+* ConvertFileFromWin7ToWin8 reads file line by line 
+
 #### 4.64.4 - 17.01.2018
 * Support for Dynamics NAV 2018 - https://github.com/fsharp/FAKE/pull/1758
 
diff --git a/src/app/FakeLib/DynamicsNavHelper.fs b/src/app/FakeLib/DynamicsNavHelper.fs
index c9207c5f411..d53d2a1b500 100644
--- a/src/app/FakeLib/DynamicsNavHelper.fs
+++ b/src/app/FakeLib/DynamicsNavHelper.fs
@@ -35,9 +35,13 @@ module Replacements =
     let ConvertFileFromWin7ToWin8 fileName =
         if isWin8 then
             traceVerbose "Converting from Win7 format to Win8"
-            Fake.StringHelper.ReadFileAsString fileName
-            |> Win7ToWin8
-            |> Fake.StringHelper.WriteStringToFile false fileName
+            let tmpFile = fileName + ".tmp"
+            Fake.StringHelper.ReadFile fileName
+            |> Seq.map Win7ToWin8
+            |> Fake.StringHelper.WriteToFile false tmpFile
+
+            File.Delete(fileName)
+            File.Move(tmpFile, fileName)
 
     let shortcutReplacements =
         ["ShortCutKey=Strg","ShortCutKey=Ctrl"
@@ -458,4 +462,4 @@ let StopNavServiceTier serverMode navClientVersion =
         StopService "MicrosoftDynamicsNavServer$DynamicsNAV80"
         StopService "MicrosoftDynamicsNavServer$DynamicsNAV90"
         StopService "MicrosoftDynamicsNavServer$DynamicsNAV100"
-        StopService "MicrosoftDynamicsNavServer$DynamicsNAV110"
\ No newline at end of file
+        StopService "MicrosoftDynamicsNavServer$DynamicsNAV110"