Deny insert/delete for all users in SQL Server 2005 In our database we have about 20 users, that is used be some program (and users are added with this program). Now there was new requirement to use 2 database and do not allow delete data from one database.

What would be easiest way to deny insert/delete access for some tables (not all)? All users have db_datareader, db_datawriter.
It would be confusing if you granted someone db_datawriter and then denied them delete rights.  So if you can, remove them from the db_datawriter and then grant them the rights they need:

create role role_MyApp
grant select, insert on Table1 to role_MyApp
...
exec sp_adduserrole 'role_MyApp, 'User1'