I'm trying to do inserts into system table - e.g. insert into sys.extended_properties values(1, 'OBJECT_OR_COLUMN', 1973582069,3, 'MS_Description', 'Code used by the State for reporting purposes') But i get this error: Msg 259, Level 16, State 1, Line 1 Ad hoc updates to system catalogs are not allowed. The reason for my doing this that there are over 600 tables in the database and the "description" for some of the columns in the tables will be the same, for example, create_date. Thus i'm trying to do a mass insert into the system tables so that i don't have go into each table and type the same description. Thank you for your help.