i try to install SQL server 2000 on windows vista, but it did not allow.
can you tell me how? and which product?

thank!!!

Unfortunately according to This they are not compatible.

Earlier versions of SQL Server, including SQL Server 2000 (all editions including Desktop Engine edition, a.k.a MSDE), SQL Server 7.0, and SQL Server 6.5, will not be supported on Windows Server "Longhorn" or Windows Vista.