Years ago I had a laptop that did that. No matter what I did it was slow. One day I ran a disc scan and noticed the HDD read slowly. I replaced the slow 4200 RPM drive with a newer model 5400 RPM drive and the boot time dropped in half.
There may be nothing at all wrong with this slow boot machine.
Bob
I have two old Win XP computers. One boots in under a minute. The other takes forever, about 4 minutes. Where should I look to solve the problem and what solutions are there?

Chowhound
Comic Vine
GameFAQs
GameSpot
Giant Bomb
TechRepublic