MSSQL locks

Use following to find blocking process

############

use master
GO
select * from sysprocesses (nolock) where blocked = 0 and spid in (
  select blocked from sysprocesses (nolock) where blocked <> 0
)
GO
#####################

To kill process which is blocking use following.

KILL 81;
GO

Use Following to find sessions or processes in the server.

sp_who2

GO