Any guess I offer is a bad one since so little was told. It could be as simple as some USB thing that takes up the startup time or as terrible as some pest or malware.
If you don't want to do the Process Explorer logging and more, try Grif's advice at link.
And unplug USB things.
--> Say, I rarely boot my machine. It has some nifty hibernation that starts in seconds (usually under 5). Are you sure you can't avoid the long boot by using the newer system?