UPDATE N
SET col1 = E.Col1, Col2 = E.Col2, ...Col_n = E.Col_n
FROM OPENROWSET('Microsoft.Jet.OLEDB.4.0','Excel 8.0;Database=c:\temp\DatiNegozi.xls', [Sheet1$]) AS E
JOIN dbo.Negozi AS N
ON E.PK = N.PK;