[Paradox] has provided tools and information on how to trick a Vista installation (x86) into acting as if it is installed on an OEM machine, which requires no product activation. Manufacturers such as Dell distribute pre-installed Vista installations on new computers.Instructions have subsequently spread and are now easily available online. Most users are reporting that the crack works just fine.
These companies embed certain license information into their hardware products, which can be validated by a Windows Vista installation, removing the need for further activation procedures. The installation required hardware-embedded BIOS ACPI_SLIC information signed by Microsoft. So this method takes advantage of how Vista validates on OEM machines.
By using a device driver, BIOS ACPI_SLIC information can be fed to Windows Vista's licensing mechanism. This, combined with an matching product key and OEM certificate, will render any system practically indistinguishable from a legit pre-activated system shipped by the respective OEM.
Instructions are available here. (Via digg)