Hello Imran,
You need to do the following, make sure Microsoft XML is loaded on your server.
I dont work for cutesoft, but I had a client site I was prototyping something for someone, and I just changed the reference to be Msxml2.DOMDocument (drop the .4.0) (they had xml 6 libraries loaded, and it would have taken a week to get any other version loaded). Everything seemed to work fine. However, remember that I dont work for CuteSoft so there may be some functionality lost by doing this.