There are three things to do that will help you out drastically and make Vista boot up REAL fast.
Now, vista has a few built-in things that start up for security and for user convenience that are HUGE and take FOREVER to load up at start.
Two of the biggest offenders that you can TOTALLY do without, are Vista Sidebar, and Windows Defender. First off, defender is gargabe. get avg anti spyware or a freebie that does NOT start up at boot and does NOT run in the back ground soaking up resources. Go to msconfig and uncheck defender and uncheck sidebar.
Next, type services.msc into the search bar on your start menu and when it shows up click on it. navigate to defender and sidebar entries. If you use sidebar, set it to a delayed start up. it wont load with the OS reducing boot time by A LOT. also, disable defender and use something a lot better. in tests, defender was one of the poorest performing anti spyware progs anyway so why bother?
Do those two things and your machine will run a LOT better.
Also, look and see what other programs you have set to load at startup in msconfig. you prolly know how to get there but just in case, i will say it anyway so someone who reads this post and doesnt, finds out how to. go to start, then type in msconfig, and when it comes up, just click on it.
Some people disable the search indexer too, in services, but its handy and doesnt really help all that much. kill defender, and kill sidebar, or atleast delay it, and you will definitely notice faster boot times.