It is not the pc, well it could be. My old sytem running windows 7 takes about the same amount of time a new dell system(optiplex 755) does to boot. A few months ago, I still had an old socket A set up and ran xp on it. It booted faster.
I say this as the hardware makes a HUGE difference. It is not all about ram and cpu. If you have a lousy board, things slow down a lot. Also, a lot of new computers use slow ram unless you spend a crap load of money on something Dell's xps machines. And like I said, the software added by those companies really sucks things down.
My 2 year old laptop with vista takes about 2 minutes to boot and that is including a number of different programs with only 1G ram. If I axe those programs, the time is about a minute or so.
I know a guy who's vista boots in under 30 seconds. He does have a raptor drive though which spins at 10,000 rpm. But another guy has an amd phenom with a regular 7200 sata drive and he gets under a minute.
See what you have to understand is dell and the others create an image with all THEIR software on it and then it gets dumped on lines of machines. This process is not always 100%
I would be willing to bet that if you had formatted the pc and had a clean install, your experience would have been different. No you should not have to do that, but it is no fault of vistas that dell, hp, gateway, and the rest do that.
And for cripes sakes, would people stop referring to me as eldar, if I wanted to be him, I would us his name.