I've installed Windows 7 x64 via Boot Camp and already installed boot camp on windows. Every time i start Windows i see a 2 minute black screen and only after that time i see the welcome screen. I have a friend who has the same problem.
Mac Specs: MacBook 2.4 GHz, 4 Gb, 320 GB 7200 RPM WD Scorpio, OS X 10.6.2, Win 7
Usually, (not always) when Windows takes an inordinate amount of time to start the fault is hardware. Every time Windows boots it has to enumerate every piece of hardware and do a registry check. Normally this goes very quickly so that it's hardly noticeable. However, on occasion a piece of hardware will cause Windows difficulty enumerating which results in a long time to boot.
This problem can get even worse if you're running an X 64 version of Windows (Vista, Win 7) since there may also be a driver problem involved. Note that Apple has not yet officially supported Win 7 - they'll do that around December with an update to Boot Camp.
Also you may have programs starting that delay the boot process:
Most often that involves anti-virus software trying to do a system scan on startup. That will hold things up for a while. AV software that checks for root kit troubles have to do their checks before the system gains control.
Go through all your startup items using the configuration editor. (from RUN type in "msconfig.exe")
