in win NT Database is going to store in SAM[security 
accounts manager]and the size of data base is 40MB,That's 
the reason we can create 40 thousand object in winNT


But in win 2000/2003 database is going ot store in NTDS and
the size of the data box is 12MB and it is extendable, In 
win 2003 we can create 1 billion objects