I am a IT Technician and do have the ability to solve many issues in regards to software problems.
However, I seem to be stuck on one issue with my own personal computer.
I have a system which has installed vista ultimate. Works fine. However as far as i can tell after the installation of SP1 my boot time increases from 10 - 20secs. To 3 - 4 minutes.
As I have dual boot this only happens when selecting Vista. The computer will sit on a black screen for 3 - 4 mins before loading.
I replaced my HDD as it was an old one anyway. Eliminating any hardware issue in regards to the HDD.
I have no clue what is causing this delay... but have read a Logitech G15 keyboard can cause this... and a few other issues.
I had some long start up times that I ended up tracing to Norton. Dumped that for ESET, and boot time plummeted. Another thing that helped was switching from the installed defragger to an aftermarket one - I use PerfectDisc, but there's other utilities as well. What you're looking for is the option to defrag system files on start up. Do that.
Computer => Properties => Advanced tools At the top of the page, you may see a message regarding performance issues.