Installing dependencies for an XNA game: Where is the XNA Framework registry path?

How do I make an NSIS installer check if the user has the XNA and .NET framew开发者_如何学Goorks installed, and install them if they aren't? (I'd rather not have it add extra prompt boxes appear, only have a page informing the user that I am making the installation).

EDIT: Due to no answer, I'll just ask this: Where is the XNA Framework in the Registry? Microsoft claims it is at HKEY_LOCAL_MACHINE\Software\Microsoft\XNA\Framework

( http://msdn.microsoft.com/library/bb464156(XNAGameStudio.40).aspx )

But I went to that path through regedit (in Windows 7), and it was not there. There was, however, an XNA folder at HKEY_CURRENT_USER\Software\Microsoft\XNA\

But not the /Framework directory.

The registry entries you are looking for are:

HKEY_LOCAL_MACHINE\Software\Microsoft\XNA\Framework\v4.0 (32-bit)
HKEY_LOCAL_MACHINE\Software\Wow6432Node\Microsoft\XNA\Framework\v4.0 (64-bit)

On my Windows 7 Ultimate 64bit machine both those checks return true.

I just finished writing an NSIS install program, here is the script I used for installing the XNA portion:

Section "XNA Framework 4.0" XNA
    #check 32bit
    ReadRegDWORD $0 HKLM "Software\Microsoft\XNA\Framework\v4.0" "Installed"
    #check 64bit
    ReadRegDWORD $1 HKLM "Software\Wow6432Node\Microsoft\XNA\Framework\v4.0" "Installed"    
    DetailPrint "32 bit XNA:"
  DetailPrint "  $0"
    DetailPrint "64 bit XNA:"
  DetailPrint "  $1"
  File "xnafx40_redist.msi"
    ${If} $0 != 1 
    ${AndIf} $1 != 1
        #they do not have framework 4 installed
        ExecWait '"msiexec" /i "$INSTDIR\xnafx40_redist.msi"  /passive'
    ${EndIf}
    Delete /REBOOTOK "$INSTDIR\xnafx40_redist.msi"
SectionEnd

Are you using Windows 7 64bit? If so you may be looking into wrong registry key. See this: http://en.wikipedia.org/wiki/WoW64#Registry_and_file_system

There is special conversion for keys in 64bit Windows, for example:

HKEY_LOCAL_MACHINE\Software\Wow6432Node 

is the 32-bit equivalent of

HKEY_LOCAL_MACHINE\Software

(although 32-bit applications are not aware of this redirection).

In NSIS you should use SetRegView 64 when reading the 64bit/native registry so you don't have to deal with Wow6432Node...