GetWindowsVersion does not work!

[richiebabes]

I was getting errors from this:

;Default installation folder
; RGM 20080606 check for Vista first
Section "Install Path"
Call GetWindowsVersion
Pop $R0
SectionEnd

${If} $R0 == "Vista"
InstallDir "blah"
${Else}
InstallDir "blah"
${EndIf}