Interesting how you somehow left out the Registry which is the biggest reason why Windows fails in the first place and is the biggest reason I left Microsoft's crap of an OS. The Registry gets clogged and requires maintenance that the end user shouldn't have to do.
What's better about the Mac in terms of this? Mac OS X's programs are all self contained in their own folder so there's no interaction of files from one program mixing with others like the way it happens in the Windows Registry which is one big reason the Windows system has so many problems. Couple that with the viruses that also get consumed in the Registry just makes the experience in Windows a big Fail.
When I'm done with a Mac program and no longer want it, I just drag the file and drop it in the trash. No worries, affects no other programs. Don't dare try that with the almighty Windows, the Registry requires the program to be uninstalled and it still leaves files in the Registry that negatively interact with other programs.
What happens when you choose to uninstall ALL of it instead of some of the files? Windows throws a fit because now other programs will be negatively impacted.
Please don't hand us the usual BS from the Windows fanboy crowd. These PC fans need to stop pretending that Windows 7 is now the end all, when it's still the same Windows. You PC fans just can't admit to it.