Lenovo is claiming that its Windows 7 certified laptops and desktops (with Windows 7 actually installed, of course) will boot-up in 30 seconds and shutdown in 10 seconds, a huge improvement from Windows Vista and even Windows XP.
The cool part is that it's the exact same hardware. In other words, install Windows XP on "Lenovo Laptop Specimen A" and it might take 60 seconds to boot up. Install Windows 7 on the same laptop and it'll only take 30 seconds.
According to Lenovo, improvements in Windows 7, some clever drivers for some of their hardware, tweaking some operating system settings, and some other alterations all make these sizable changes possible.
Read more at the About.com Computing Center:
Lenovo Claims Fastest Windows 7 Boot Time by Eric Lai, Computerworld