Check For .NET Framework 4.5

If DotCheck() Then
    WScript.Echo "Exists!"
End If

Function DotCheck()
    strComputer = "."
    Set objWMIService = GetObject("winmgmts:\\" & strComputer & "\root\cimv2")
    Set colItems = objWMIService.ExecQuery("Select Name, Version from Win32_Product Where Name Like 'Microsoft .NET Framework%'")
    DotCheck = False
    For Each objItem in colItems
        If InStrRev(objItem.Version, "4.5.") Then
            DotCheck = True
            Exit For
        End If
    Next
End Function