Index: win_installer/src/Functions.nsh
===================================================================
diff -u -ra8e6dab9a52c98bfc9886b92c7794a3f5ef21cff -r1c44bb49957cacc6ab070a0e27f7e26bb726e66f
--- win_installer/src/Functions.nsh	(.../Functions.nsh)	(revision a8e6dab9a52c98bfc9886b92c7794a3f5ef21cff)
+++ win_installer/src/Functions.nsh	(.../Functions.nsh)	(revision 1c44bb49957cacc6ab070a0e27f7e26bb726e66f)
@@ -104,3 +104,99 @@
   Pop $R1
   Exch $R0
 FunctionEnd
+
+/**
+* Source - Afrow UK http://nsis.sourceforge.net/VersionCompare
+*
+* Compare version numbers.
+*
+* Syntax:
+* ${VersionCompare} "[Version1]" "[Version2]" $var
+*                     ;    $var=0  Versions are equal
+*                     ;    $var=1  Version1 is newer
+*                     ;    $var=2  Version2 is newer 
+**/
+Function VersionCompare
+    !define VersionCompare `!insertmacro VersionCompareCall`
+ 
+    !macro VersionCompareCall _VER1 _VER2 _RESULT
+        Push `${_VER1}`
+        Push `${_VER2}`
+        Call VersionCompare
+        Pop ${_RESULT}
+    !macroend
+ 
+    Exch $1
+    Exch
+    Exch $0
+    Exch
+    Push $2
+    Push $3
+    Push $4
+    Push $5
+    Push $6
+    Push $7
+ 
+    begin:
+    StrCpy $2 -1
+    IntOp $2 $2 + 1
+    StrCpy $3 $0 1 $2
+    StrCmp $3 '' +2
+    StrCmp $3 '.' 0 -3
+    StrCpy $4 $0 $2
+    IntOp $2 $2 + 1
+    StrCpy $0 $0 '' $2
+ 
+    StrCpy $2 -1
+    IntOp $2 $2 + 1
+    StrCpy $3 $1 1 $2
+    StrCmp $3 '' +2
+    StrCmp $3 '.' 0 -3
+    StrCpy $5 $1 $2
+    IntOp $2 $2 + 1
+    StrCpy $1 $1 '' $2
+ 
+    StrCmp $4$5 '' equal
+ 
+    StrCpy $6 -1
+    IntOp $6 $6 + 1
+    StrCpy $3 $4 1 $6
+    StrCmp $3 '0' -2
+    StrCmp $3 '' 0 +2
+    StrCpy $4 0
+ 
+    StrCpy $7 -1
+    IntOp $7 $7 + 1
+    StrCpy $3 $5 1 $7
+    StrCmp $3 '0' -2
+    StrCmp $3 '' 0 +2
+    StrCpy $5 0
+ 
+    StrCmp $4 0 0 +2
+    StrCmp $5 0 begin newer2
+    StrCmp $5 0 newer1
+    IntCmp $6 $7 0 newer1 newer2
+ 
+    StrCpy $4 '1$4'
+    StrCpy $5 '1$5'
+    IntCmp $4 $5 begin newer2 newer1
+ 
+    equal:
+    StrCpy $0 0
+    goto end
+    newer1:
+    StrCpy $0 1
+    goto end
+    newer2:
+    StrCpy $0 2
+ 
+    end:
+    Pop $7
+    Pop $6
+    Pop $5
+    Pop $4
+    Pop $3
+    Pop $2
+    Pop $1
+    Exch $0
+FunctionEnd