Description of problem:
In the Directory Console, when you click on user that was synced 
from Directory Server, and open the properties page, if you click 
on the NT User, and uncheck the "Enable NT User Attributes" 
check box and attempt to save, you will get the following error:

"Cannot save to directory server:
error result (65);  Object class violation"

I'd like to keep the account in Directory Server and remove the windows account. 
 How do I do it?

Thanks

Denise