We had purchased 2009 AutoCad LT and just upgraded to 2014 AutoCad LT. Upgrade was downloaded but when tried installing upgrade we received an error at the Autodesk Self Extract Window as follows: "A cabinet file necessary for installation cannot be trusted. Please verify the crytographic Service are enabled and the cabinet file certificate is valid". Please advise as how to proceed.
I tried to search on Google about the error warning. Apparently it is related to DirectX installation.
Try >> this solution << I found on Microsoft forum.