Hi,
Check whether the M/B chipsets are the same and also the driver version, there are differences between an OEM install and a normal install, a lot of OEM's disable the access to this for whatever reason, that's why I always do a full install, which always comes up the same.

>Hi All
>
>I have two boxes with the same hdd, drivers, and controllers, same Windows, etc. On the one I have the option to enable/disable write behind cache under the hardware properties tab - disk drives node. On the other machine this option is not selectable, it is greyed out, and the check box appears to not be selected. Why can I access the check box on the one machine but not on the other when to all intents and purposes these are identical machines.