Mine; about 3-5 minutes to be able to use it properly, lol.
TF I'm upgrading now, I'm going spare at my computer now, I'm even surprised it hasn't been launched through my window yet.
sometimes i would have to restart the whole process while my Anti virus was updating or scanning
and once or twice had to leave the house without a peek at my favourate forums, It was time to upgrade
as fast as a tortoise...
Watch these. Its for vista though.

40 - 50 Seconds till everything's loaded on desktop, about 3 Mins till computers completely idle.
Whats the fastest HDD out right now or available on OCUK?

Just found this script that times your boot up.
http://www.vistax64.com/overclocking-cooling/153134-reboot-time.html
Works a treat.
Just did it and got 99 seconds which is weird. I just overclocked my pc to 3ghz and its still sluggish at booting up. No idea what could be causing it to hang.
after switching to auto loggin my time is 78secs http://www.vistax64.com/tutorials/70563-boot-up.html