setRequestHeader a propertysine deger vererek degistirebilirsiniz.

    Set xmlHttp = Server.Createobject("MSXML2.ServerXMLHTTP")
    xmlHttp.Open "GET", "https://www.r10.net" False
    xmlHttp.setRequestHeader "User-Agent", "GoogleBot"
    xmlHttp.setRequestHeader "content-type", "application/x-www-form-urlencoded"
    xmlHttp.Send
    Response.Write xmlHttp.responseText
    set xmlHttp = Nothing