how to disable is identity of a column in table

Dear Vijay

The above code will only disable the identity, if you have to remove the identity altogether there is the steps below.

--If other tables' foreign keys point to the IDENTITY column, drop them. Here, the script drops
--the foreign key pointing to Orders2.OrderID from OrderDetails2.
ALTER TABLE OrderDetails2
DROP CONSTRAINT FK_OrderDetails2_Orders2

--If a primary key exists on the IDENTITY column, drop the primary key constraint the way this
--script drops the primary key from Orders2.
ALTER TABLE Orders2
DROP Constraint PK_Orders2

--Add another column with the same data type as the IDENTITY column to Orders 2 and allow
--NULLs.
ALTER TABLE Orders2
ADD new_OrderID int NULL

--Update the new column with the values of the IDENTITY column.
UPDATE Orders2
SET new_OrderID = OrderID

--If the new column doesn't permit NULLs, alter the column to NOT NULL.
ALTER TABLE Orders2
ALTER COLUMN new_OrderID int NOT NULL

--Drop the IDENTITY column.
ALTER TABLE Orders2
DROP COLUMN OrderID

--Rename the new column to the dropped IDENTITY column's name.
EXEC sp_rename 'Orders2.new_OrderID', 'OrderID', 'COLUMN'

--If a primary key exists on the new column, recreate the key. In this case you recreate the
--primary key on Orders2.
ALTER TABLE Orders2
ADD CONSTRAINT PK_Orders2 PRIMARY KEY(OrderID)

--On other tables, recreate any foreign keys that originally pointed to the old IDENTITY column
--and point them to the new column. Here, you recreate the foreign key on OrderDetails2.
ALTER TABLE OrderDetails2 WITH NOCHECK
ADD CONSTRAINT FK_OrderDetails2_Orders2
FOREIGN KEY(OrderID)
REFERENCES Orders2(OrderID)

SET IDENTITY_insert  tbbranchheadoffice on
insert into tbbranchheadoffice(id,name,dob,fathersname)values(85,'Vk','dsfsd','dsfs')

hey dude..

see this link

surely we you will get answer.. :)