The following seems to work:
UPDATE Menu2 SET Count=Temp.RecordCount FROM Menu AS Menu2 JOIN (SELECT Menu.Numero,COUNT(*) AS RecordCount
FROM Menu
INNER JOIN MenuEntity ON Menu.Numero=MenuEntity.NoMenu
INNER JOIN MenuPrivilege ON Menu.Numero=MenuPrivilege.NoMenu
INNER JOIN MenuRole ON Menu.Numero=MenuRole.NoMenu
INNER JOIN DBUsers ON MenuEntity.NoEntity=DBUsers.NoEntity AND MenuPrivilege.NoType=DBUsers.NoType AND MenuRole.NoRole=DBUsers.NoRole
WHERE Menu.Numero NOT IN (SELECT Menu.Numero FROM MenuPrivilegeExceptionCase
INNER JOIN Menu ON MenuPrivilegeExceptionCase.NoMenu=Menu.Numero
WHERE MenuPrivilegeExceptionCase.NoMember=DBUsers.AI)
GROUP BY Menu.Numero
UNION
SELECT Menu.Numero,COUNT(*) AS RecordCount
FROM Menu
INNER JOIN MenuPrivilegeExceptionCase ON Menu.Numero=MenuPrivilegeExceptionCase.NoMenu AND
MenuPrivilegeExceptionCase.Enabled=1
INNER JOIN MenuEntity ON Menu.Numero=MenuEntity.NoMenu
INNER JOIN DBUsers ON MenuEntity.NoEntity=DBUsers.NoEntity
WHERE MenuPrivilegeExceptionCase.NoMember=DBUsers.AI
GROUP BY Menu.Numero) Temp ON Temp.Numero=Menu2.Numero
