When you insert into the table, use getdate() as the value for the DateCreated field:
insert into mytesttable (MyDateField) values (getdate())
Or, to make a default value of the current datetime, in design view in the Enterprise Manager type (getdate()) in the Formula field for the table. Or, when you create the table in the Query Analyzer, do it this way:
CREATE TABLE [MyTestTable] (
[IDColumn] [int] IDENTITY (1, 1) NOT NULL ,
[DateCreated] AS (getdate())
) ON [PRIMARY]
--EricDV Sig--------- Some problems are so complex that you have to be highly intelligent and well informed just to be undecided about them. - Laurence J. Peters