PCs from Hewlett-Packard Gateway, Lenovo, and other major computer makers that contain a widely used Intel chipset can't be upgraded to Windows Vista Service Pack 1 if they're running certain drivers.
Microsoft has said that Vista SP1 won't work with "a small number of device drivers." The list, however, includes drivers for an Intel chipset that's found in thousands of PCs and laptops.
The affected chipset is Intel's 945G Express series, which is used in computers from virtually all major system vendors. It's also found on standalone motherboards sold by Asus. The 945G Express chipset driver versions between numbers 22.214.171.1242 and 126.96.36.1993 won't work with Vista SP1, according to Microsoft.