Eu escrevi esta consulta:

UPDATE tbl_stock1 SET 
tbl_stock1.weight1 = (
    select (b.weight1 - c.weight_in_gram) as temp 
    from
        tbl_stock1 as b,
        tbl_sales_item as c 
    where
        b.item_submodel_id = c.item_submodel_id 
        and b.item_submodel_id = tbl_stock1.item_submodel_id 
        and b.status <> 'D' 
        and c.status <> 'D'
    ), 
tbl_stock1.qty1 = (
    select (b.qty1 - c.qty) as temp1 
    from
        tbl_stock1 as b,
        tbl_sales_item as c 
    where 
        b.item_submodel_id = c.item_submodel_id 
        and b.item_submodel_id = tbl_stock1.item_submodel_id 
        and b.status <> 'D' 
        and c.status <> 'D'
    )
WHERE
    tbl_stock1.item_submodel_id = 'ISUBM/1' 
    and tbl_stock1.status <> 'D';

Eu recebi esta mensagem de erro:

Operation must use an updatable query. (Error 3073) Microsoft Access

Mas se eu executar a mesma consulta no SQL Server, ela será executada.

Obrigado, dinesh