I think I found the solution.................make the current user account as standard user..............then create a new user with administrative privilege..............then login to the new administrative account...........try installing again.............I think it is going to work.
After installation you may find incompatibility issue which may prevent you from starting the application...............right click on autocad icon>go to properties> compatibility >check-run this program in compatibility mode for windows xp(service pack 3) and Run this program as an administrator>go to change setting for all users and check the same options>apply and OK.................then run the program........a popup screen will appear ...............check -Don't show this message again and Run program.
Note:This solution willwork only for AutoCAD 2006 and 2007.
Let me know if this help you at Email Removed