If you have a habbit of installing a lot of small programs all the time eventually it will be slower.. Of course if you just install the machine and then dont really install anything a WinPC runs fine..
But most software around for Windows seems poor and together with Windows they always create a mess of files, registrations, errors etc.. Install / uninstall works in a crap way and there is always loads of leftovers etc..
But I also try to stay away from formating as that is even more irritating because if you do it too often your valid key for Windows suddenly needs a change and that is always a lot of calling, pressing numbers and talking with stupid support etc.. And that's the customers that bought there software that are treated that way... Pirated software seems free of all that rubbish - again why I hate MS lol
I have to agree that program un-installs and re-formats can be some of the most time consuming and irritating experiences surrounding the PC. I used to be in a bad habit of formatting my system every 1-2 months for a bunch of different reasons, and eventually my key stopped working as well. I got so fed up punching in numbers and talking to MS people that I gave up on them and I've been using a downloaded copy of XP ever since.
It's been really fun listening to both sides of the story from you guys. You each have good points to consider.