Re: in business it is the applications that matter.
.. or the vendor of the application going "That is not a supported configuration" and refusing to touch it with a ten metre pole AND voiding the stupidly expensive support contract over it.
Or the regulatory agency refusing to certify said install of application because the vendor won't touch that configuration with a 10 metre pole.
Windows can be stable. (I hear you laughing, shut up for a minute and let me finish.)
IF it's running on solid hardware with solid drivers, and the application is written so that it's not trying to do stupid tricks around the OS (or make the OS do stupid tricks), then... yes. I've seen multi-year uptimes on a machine running.... Windows. (We only needed to reboot it because of a very slow, very well known memory leak and the only fix for it is... rebooting the machine.)
I've yet to see an application for the specific line of business [RedactedCo] is in written in anything other than windows for a desktop client. Server side? An older iteration of this LOB application from this vendor ran on a PowerPC server running AIX... and it was coded in BASIC.(1) And it was frankly pretty shite. Not saying the windows version of the app we migrated to was any better, but the OS really didn't contribute to the product's stability or usability- none of the problems we've had with the windows flavor of the server side app was directly attributed to the OS, the underlying hypervisor(2), or the underlying hardware.(3)
From what I understand, another vendor in this industry use an app that runs on an AS/400 for the server side, and... windows for the client. SO... Yeah. Some of us are unfortunately stuck with windows because changing the underlying OS requires a galactic shift in how the industry writes their software, and that's not going to happen even in a couple years of dedicated, sustained effort.
Come talk to me when all I have to do to make a windows app play nice on linux is to point the WINE configurator at the installer for it, walk away for a cup of coffee, and come back down and start the app up flawlessly without having to nursemaid it, figure out what tiny tiny library WINE forgot to install, didn't install properly, or doesn't work at all because ONE of the dependencies decided to shift it's paradigm without a clutch and no one's gotten around to fixing it after a year or two.
1. Yeah. NOT C, or any of the other more traditional complied or scripted languages you'd find on a POSIX-compliant OS. Friggin BASIC.
2. We had a small amount of discussion with that vendor about running the database servers in a VM for production, but when we pointed out that we were running it in the lab on a VM and it was solid, they shut up, more or less.
3. Same with us using a storage appliance using this radical new technology called iSCSI (well, new for them, but by 2012 it was pretty well understood...) from a vendor not on their 'approved' list... And yet despite their kvetching about performance, we proved conclusively that the performance issues their product had was shite database indexing and query design, NOT the hardware.