NSIS installer that checks for .NET Framework

Question

I want to create an NSIS installer that checks for the .NET Framework and installs it if it\'s not there. Can you point me to a script for this? I\'m very new to NSIS.

Answer 1

!define DOT_MAJOR "2"
!define DOT_MINOR "0"

Function IsDotNetInstalled

  StrCpy $0 "0"
  StrCpy $1 "SOFTWARE\Microsoft\.NETFramework" ;registry entry to look in.
  StrCpy $2 0

  StartEnum:
    ;Enumerate the versions installed.
    EnumRegKey $3 HKLM "$1\policy" $2

    ;If we don't find any versions installed, it's not here.
    StrCmp $3 "" noDotNet notEmpty

    ;We found something.
    notEmpty:
      ;Find out if the RegKey starts with 'v'.  
      ;If it doesn't, goto the next key.
      StrCpy $4 $3 1 0
      StrCmp $4 "v" +1 goNext
      StrCpy $4 $3 1 1

      ;It starts with 'v'.  Now check to see how the installed major version
      ;relates to our required major version.
      ;If it's equal check the minor version, if it's greater, 
      ;we found a good RegKey.
      IntCmp $4 ${DOT_MAJOR} +1 goNext yesDotNetReg
      ;Check the minor version.  If it's equal or greater to our requested 
      ;version then we're good.
      StrCpy $4 $3 1 3
      IntCmp $4 ${DOT_MINOR} yesDotNetReg goNext yesDotNetReg

    goNext:
      ;Go to the next RegKey.
      IntOp $2 $2 + 1
      goto StartEnum

  yesDotNetReg:
    ;Now that we've found a good RegKey, let's make sure it's actually
    ;installed by getting the install path and checking to see if the 
    ;mscorlib.dll exists.
    EnumRegValue $2 HKLM "$1\policy\$3" 0
    ;$2 should equal whatever comes after the major and minor versions 
    ;(ie, v1.1.4322)
    StrCmp $2 "" noDotNet
    ReadRegStr $4 HKLM $1 "InstallRoot"
    ;Hopefully the install root isn't empty.
    StrCmp $4 "" noDotNet
    ;build the actuall directory path to mscorlib.dll.
    StrCpy $4 "$4$3.$2\mscorlib.dll"
    IfFileExists $4 yesDotNet noDotNet

  noDotNet:
    ;Nope, something went wrong along the way.  Looks like the proper .NETFramework isn't installed.  
    Push "NOK"
    Return

  yesDotNet:
    ;Everything checks out.  Go on with the rest of the installation.
    Push "OK"
    Return

FunctionEnd