Some applications like autocad require the current user to be logged in as an administrator in order to use them and as you can imagine thats not a good idea. Esp if this makes you give admin access to users who are likely to install random software and otherwise mess up a perfectly good system.
To avoid this situation follow the following instructions by Anomic Anomaly posted on the Security Basics mailing list:
1. Grab ‘FileMon’ and ‘RegMon’ (both free) from SysInternals
2. Run AutoCad and monitor the changes made to the filesystem and registry.
3. Modify permissions only on those specific areas and give the user access to them
4. Watch your users happily run AutoCad as a User.
– Suramya