diff --git a/ChangeLog b/ChangeLog
index d1ce9c7dc..9e804959e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,9 @@
 2007-05-07  Enrico Tröger  <enrico.troeger@uvena.de>
 
  * data/filetypes.haskell: Added build instructions.
+ * geany.nsi: Prevent installation in a directory without proper
+              write permissions under Windows.
+              Display an error message instead.
 
 
 2007-05-06  Enrico Tröger  <enrico.troeger@uvena.de>
diff --git a/geany.nsi b/geany.nsi
index c7e6b5128..fe07d37ec 100644
--- a/geany.nsi
+++ b/geany.nsi
@@ -20,7 +20,7 @@
 !define RESOURCEDIR "geany-${PRODUCT_VERSION}"
 
 ; only used when embedding GTK+ installer
-!define GTK_INSTALLER "gtk+-2.8.18-setup-1.exe"
+!define GTK_INSTALLER "gtk+-2.10.6-1-setup.exe"
 
 SetCompressor /SOLID lzma
 XPStyle on
@@ -89,6 +89,7 @@ FunctionEnd
 ; Components page
 !insertmacro MUI_PAGE_COMPONENTS
 ; Directory page
+!define MUI_PAGE_CUSTOMFUNCTION_LEAVE OnDirLeave
 !insertmacro MUI_PAGE_DIRECTORY
 ; Start menu page
 var ICONS_GROUP
@@ -145,7 +146,7 @@ SectionEnd
 
 Section "Documentation" SEC03
   SectionIn 1
-  SetOverwrite try
+  SetOverwrite ifnewer
   SetOutPath "$INSTDIR"
   File /r "${RESOURCEDIR}\doc"
 
@@ -169,7 +170,7 @@ SectionEnd
 
 ; Include GTK runtime library but only if desired from command line
 !ifdef INCLUDE_GTK
-Section "GTK 2.8 Runtime Environment" SEC05
+Section "GTK 2.10 Runtime Environment" SEC05
   SectionIn 1
   SetOutPath "$INSTDIR"
   SetOverwrite ifnewer
@@ -243,6 +244,23 @@ Function un.onInit
   Abort
 FunctionEnd
 
+Function OnDirLeave
+  ClearErrors
+  SetOutPath "$INSTDIR" ; what about IfError creating $INSTDIR?
+  GetTempFileName $1 "$INSTDIR" ; creates tmp file (or fails)
+  FileOpen $0 "$1" "w" ; error to open?
+  FileWriteByte $0 "0"
+  IfErrors notPossible possible
+
+notPossible:
+  RMDir "$INSTDIR" ; removes folder if empty
+  MessageBox MB_OK "The given directory is not writeable. Please choose another one!"
+  Abort
+possible:
+  FileClose $0
+  Delete "$1"
+FunctionEnd
+
 Section Uninstall
   !insertmacro MUI_STARTMENU_GETFOLDER "Application" $ICONS_GROUP
   Delete "$INSTDIR\${PRODUCT_NAME}.url"