Check architecture (x86, x64 or ia64)

Check wether AMD64 or Itanium 64bit processor - Winamp & Shoutcast Forums

http://forums.winamp.com/showthread.php?threadid=299034

Are you a developer who uses NSIS to distribute your application? Are you a Winamp plug-in developer who wants to use NSIS to distribute your plug-in? Have suggestions for other people like you? This is the place.

!include WinVer.nsh

${If} ${AtLeastWinXP}

    System::Alloc 36

    pop $0

    ${If} $0 <> 0

        System::Call 'kernel32::GetNativeSystemInfo(i $0)'

        System::Call "*$0(&i2.r1)"

        MessageBox mb_ok wProcessorArchitecture=$1

        System::Free $0

    ${EndIf}

${EndIf}