Try installing/uninstalling a lot of programs, doing a lot of work with a lot of programs, perhaps some basic multitasking and you'll see how 'stable' it is.
Your claims are getting more and more ridiculous by the minute, and I'm starting to suspect you haven't been near a Windows PC since the Win98 days. Just stereotypical, sweeping PC-hater clichées about instability, malware and the Windows registry, without any concrete examples to back it up. Malware? You don't get malware unless you're a clueless 13-year old who installs everything that moves, clicks "Yes" in every popup dialog on Eastern European porn sites and downloads tons of apps and games with embedded malware from Pirate Bay. I've never used AntiVirus software regularly in my 17 years with Windows. Once every 6 months or so I install an AntiVirus app and do a thorough scan, but I barely see the point anymore as they always come up empty handed.
Do you actually believe there's
any PC user who doesn't do basic multitasking? I use Vista for at least 8 hours a day and I usually have 6-7 apps running a typical snapshot of my screen on any given day would have Photoshop, Flash, Excel, Outlook, iTunes or Windows Media Player, IE or Safari, and sometimes audio applications like Cubase, Wavelab and Reason. I did the same in XP, Win2K and Win98, at a time when basic multitasking was virtually a no-go on Macs because they didn't even have dynamic RAM allocation before OS X, you had to pre-allocate RAM for each application.
As for uninstalling/installing programs, you're on thin ice if you're going to defend the Mac in that respect. It used to be that you'd simply drag Mac apps to the Trash and they'd be "uninstalled", but nowadays app installations spew crap all over a Mac and if they weren't nice enough to provide you with an uninstallation script, or you weren't careful enough to save it, you have to go hunting for residual files in weird corners of the system. Once I installed a driver and software for a Yamaha firewire audio device on my iMac, and when I decided I was better off moving the Yamaha 01X back to the PC and uninstalled the driver using the provided script, I got the Leopard BSOD. I looked for hours until I finally found some miniscule MIDI settings file that Yamaha had missed in their script. And good luck trying to get rid of Logitech Control Center, should you ever have the guts to install that on a Mac. OS X is in sore need of a unified installation process and some sort of install/uninstall applet.
OS X is fine. Vista is fine. They're both stable, with the occasional odd crash once a week or so. They both have their pros and cons. Vista is ugly to look at with all its dazzling colors in the wrong places, OS X has networking capabilities from the 1950's. Vista bothers the hard disk too much with all its incessant background processes like SuperFetch, Defender and Defrag, OS X has a bloody annoying and primitive Software Update applet that always wants to reboot the system for every miniscule little "Camera Raw" update I don't want or need. None of this will stop me from getting my work done. Just give me the right apps installed on either platform and I'll get to work.