Why do i get a Download of Specified resource has failed error when using XMLDOM?

Best method to debug this issue is to run the requested url / page separately and check for errors.

Additionaly you may do the following to troubleshoot the issue as this is more like a permissions error. Anonymous IIS account cannot access the resource but you can.

Try following
1. Insert a Response.write(Server.HTMLEncode(xmlHTTP.ResponseText)) command
just after requesting the file on the server. If you get back the correct
data, then it's not a permissions error.
2. Check if requests are reaching the requested page in server.