You can RESEED
?Identity Columns of all tables by using sp_MSForEachTable
?to loop through all the tables and executing the DBCC CHECKIDENT
?command if the specific table has an identity column:
EXEC sp_MSForEachTable ' IF OBJECTPROPERTY(object_id(''?''), ''TableHasIdentity'') = 1 DBCC CHECKIDENT (''?'', RESEED, 0)