ActiveX component cant create object AcroExch.App

I have read an article about accessing PDF's using Acrobat SDK and downloaded Acrobat 7.0.5 SDK version and installed it.

Later I have uninstalled the 7.0.5 SDK version, downloaded SDK8_v2_Full_win.zip and extracted it to C:\Program Files\Adobe folder. I have acrobat reader 8.1.0 installed in my machine.

Now when I run the following code from an automation tool (QTP),Iam getting an error : ActiveX component cant create object AcroExch.App .

Option Explicit
Dim gApp, gPDDoc, jso
Set gApp = CreateObject( "AcroExch.App" )
Set gPDDoc = CreateObject( "AcroExch.PDDoc" )
If gPDDoc.Open( "c:\MyPdfFile.pdf" ) Then
Set jso = gPDDoc.GetJSObject()
jso.console.Show
jso.console.Clear
jso.console.println ( "Hello, Acrobat for QuickTest!" )
gApp.Show
End If
Set jso = Nothing : Set gPDDoc = Nothing : Set gApp = Nothing

Article author told me to check the following keys in registry: -
HKEY_CLASSES_ROOT\AcroExch.App
HKEY_CLASSES_ROOT\AcroExch.App.1
HKEY_CLASSES_ROOT\AcroExch.AVDoc
HKEY_CLASSES_ROOT\AcroExch.Document

I was able to find only 'AcroExch.Document' key in registry my machine.

"AcroExch.App" is not registered, that's why I got the eroor and installation of the SDK did not work in my system.

Please let me know how to get acrobat SDK successfully installed?