update installer stuff

Utils/NSIS/readme.txt

@@ -1,8 +1,8 @@
 In this folder are local copies of things required to properly build the
 StepMania installer.
 
-Right now, this is just the GetVersion plugin (so that we can write the files
+Right now, this is just the NSIS-OS plugin (so that we can write the files
 to somewhere that isn't Program Files on Windows Vista/7).
 
-The GetVersion plugin can alternatively be downloaded from here:
-http://nsis.sourceforge.net/GetVersion_%28Windows%29_plug-in
+The NSIS-OS plugin can be alternatively downloaded from here:
+http://nsis.sourceforge.net/NSIS-OS_plug-in

sm-ssc.nsi

@@ -54,14 +54,6 @@
 	; I think it may need actual admin privs for writing to the registry... -aj
 	;RequestExecutionLevel user
 
-	;GetVersion::WindowsServicePackMajor
-	;Pop $R0
-	;${If} $R0 >= 6
-	;	vista & 7
-	;${Else}
-	;	xp and below
-	;${EndIf}
-
 	InstallDir "$PROGRAMFILES\${PRODUCT_ID}"
 	InstallDirRegKey HKEY_LOCAL_MACHINE "SOFTWARE\${PRODUCT_ID}" ""
 
@@ -97,9 +89,6 @@
 
 	!insertmacro MUI_PAGE_WELCOME
 
-	; include various Windows-only notices
-	!insertmacro MUI_PAGE_LICENSE ".\Docs\WindowsNotes.txt"
-
 	;!insertmacro MUI_PAGE_COMPONENTS
 	!insertmacro MUI_PAGE_DIRECTORY
 	!insertmacro MUI_PAGE_INSTFILES
@@ -681,6 +670,12 @@ FunctionEnd
 
 Function .onInit
 
+	nsisos::osversion
+	${If} $R0 >= 6
+		;vista & win7
+		StrCpy $INSTDIR "%HOMEPATH%\${PRODUCT_ID}"
+	${EndIf}
+
 	; Force show language selection for debugging
 	;!define MUI_LANGDLL_ALWAYSSHOW
 	!insertmacro MUI_LANGDLL_DISPLAY