Thank you very much, I'll be using Linux. The only problem is that I will have to dual-boot with Vista just so I can run Office and a couple other aps that I am sure that people will expect me to have just because I tend to work in places that use Windows, and that irritates me.
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You can get Office for Mac. It works great, in fact. The thing is that people for years have always liked PC for cost, and Mac for OS - but with this last release(and it is UNIX, btw, albeit the world's fanciest version of it - heh) it runs on Intel chips. All Macintosh computers now are running Intel chips and they just released a new vrsion of Bootcamp that finally does allow for dual-boot. Win XP/2K for your games, Mac OS for everything else - and honestly, it does EVERYTHING ELSE. Yet, there are a few apps you need PC - well, presto - reboot and enjoy.
The next version, though, is amazing. No more Apple hardware.
From an IT perspective:
Apple/Unix - $60 a copy when bought in bulk. No hardware upgrades required. Legacy apps supported via XP or 2K or NT on second partition. No registration, nanny-ware, virtually no viruses and mal-ware to deal with for normal applications. Versions of every major product for office use available for the same price(or better, since Apple gives massive discounts to businesses and educational institutions).
And all using the same hardware you have. You don't even have to add memory to any of them. Works with your ancient laptops and your servers. You can even keep your SQL server running windows 2K/NT if you want.
20 computers. 12 PCs, 4 laptops, 4 server machines. One person to manage it all. No calling home, no yearly fees. Just an OS that you use as you wish. Also, dead-simple to repair and fix. Just drop in a new OS folder and rearrange a few things(15 minutes tops) and presto - back in business.
Total cost to upgrade/install new OS for 20 machines? $800.
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Windows -
16 copies of Vista. 4 new laptops(since upgrading older laptops isn't an option). 16 machines need new memory and a few need new power supplies, video cards, hard drives, and so on. 4 servers require the full-blown mega version of Vista(OUCH).
New firewall software, big changes to the servers, new version of SQL if you use it... new versions of most of your apps or upgrades(that is if you bought legitimate copies of everything for every computer, which most businesses don't)
And you need two peolpe to manage 20 computers and the network. Horrendous phase-in schedule and back-end work.
Total cost to upgrade 20 machines? $20K or more, plus all the nanny-ware and the extra person you pay salary to.
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DUH.

Microsoft should be giving their OS away for nearly free, because the second that you can run Mac and PC on the same box without any upgrade(and UNIX if you want to go for seamless tri-boot), people will ditch them in a heartbeat. Cheaper, faster, company that's not burning their bridges... Mostly, though... cheaper. And just look at Wal-Mart. Cheaper is the #1 factor in business.
Me? I have a copy of XP Pro I bought a few months ago. It will serve me for years while at the same time I run Mac OS or Unix and phase our my legacy apps.(90% of which are games). In five years, none of my old games will be worth playing anyways or will have UNIX/Mac ports of them(like Unreal Tournament). I'm never touching Vista since every last app and game for the next five years will have to support XP anyways or loose massive potential sales.
Cost to me will be a paltry $100 or less. And Apple is a great company to work with as a business owner or customer compared to Microsoft. Customer service is worlds better than a decade ago.