I'm not surprised you're having a problem downloading "MS Autocad" because
such a program does not exist. First of all, Autocad is a drawing program
product published by the Autodesk corporation, a competely different company
from MS. And secondly, I would be very surprised if it was legally
available for download as Autocad is quite an expensive program, costing
well over $3500 US for the current version.
There is a drawing program somewhat similar to Autocad available from
Microsoft called Visio which you can purchase from your favourite software
vendor. There is a downloadable trial version available on the MS web site
at
http://www.microsoft.com/office/visio/prodinfo/trial.mspx
