Windows Phone 8.1
Windows Phone 8.1 is the best update yet, thanks to its revamped design and modern features, but it lags behind iOS and Android.
Pricing not available
Mac OS X 10.9 Mavericks
As it's a free upgrade that gives you more apps, improved features across the board, and better performance, there is really no reason not to get Mavericks on your Mac.
Apple iOS 7
Provided you take the time to find your way around, iOS 7's new design makes it a compelling upgrade that completely transforms Apple's mobile OS.
Microsoft Windows 8 Pro ( Upgrade)
Microsoft makes an aggressive, forward-thinking, and bold statement for the future of PCs with Windows 8, and vast security and speed improvements more than justify the $40 upgrade price.
Apple Mac OS X 10.6.3 Snow Leopard
Intel Mac users will like Snow Leopard's smartly designed interface enhancements, and its Exchange support is a must-have (especially with Outlook for Mac on the way). With a ton of technological improvements, Snow Leopard is worth the $29 upgrade fee.
Microsoft Windows 7 Ultimate
Windows 7 is more than what Vista should have been, it's where Microsoft needed to go. How much damage Vista did and whether Windows 7 is enough for people to finally abandon Windows XP are questions that nobody has the answers to right now.
Mac OS X 10.5 Leopard
The grace of Leopard's interface enhancements makes productivity more pleasurable with a Mac, as more than 300 functional and fun features top off this update.
Apple Mac OS X 10.4 Tiger ( Family Pack)
Though its new user features have mixed appeal, Tiger's technological changes and speed improvements make this an enticing upgrade, especially for those who passed on Panther.
Windows Vista Home Basic
Windows Vista Home Basic is essentially warmed-over Windows XP, Windows XP SP3. If you're currently happy with Windows XP SP2, we see no compelling reason to upgrade. On the other hand, if you need a new computer right now, Windows Vista is stable enough for everyday use.
Windows Vista Home Premium
Windows Vista Home Premium is essentially warmed-over Windows XP Home Edition. If you're currently happy with Windows XP SP2, we see no compelling reason to upgrade. On the other hand, if you need a new computer right now, Windows Vista Home Premium is stable enough for everyday use.
Windows Vista Business
Windows Vista Business is essentially warmed-over Windows XP. If you're currently happy with Windows XP SP2, we see no compelling reason to upgrade. On the other hand, if you need a new computer right now, Windows Vista is stable enough for everyday use.
Microsoft Virtual PC for Mac 7.0
Microsoft Virtual PC for Mac 7.0 is slow and a bit expensive, probably because it includes a Windows license, but it's cheaper than buying and maintaining a real PC--even a low-end one.
Microsoft Windows XP Home Edition w/SP2
We recommend installing Windows XP SP2 but only after Microsoft has had a few weeks to work out the kinks.
Microsoft Small Business Server 2003
For small businesses that need a business in a box and want to stick with Microsoft technology, SBS 2003 is the only game in town.
Apple Mac OS X 10.3 Panther
Panther adds new and useful features, but at the expense of some old standbys. Current Jaguar users need not apply.
Virtual PC 6.0 for Mac
Virtual PC 6.0 is the best way to run Windows on OS X, but it's not worth the price for older Macs.
Red Hat Linux 8.0 Professional
Red Hat remains a solid Linux contender, but Windows switchers or dual-booters should stick with SuSE for easier installation.
Virtual PC 5.0 for Windows
Virtual PC for Windows 5.0 boosts performance over the last version. It's the best emulator around for running multiple Windows or Linux OSs on one PC.
Microsoft Windows XP Service Pack 1
Windows XP's first service pack is a worthwhile download--if only for the security patches--as long as you have the bandwidth. If not, you're better off piecing together XP fixes in smaller, single downloads.
Pricing not available
Mac OS X 10.2 Jaguar
Take a good, hard look at Mac OS X 10.2 if you're adding a Mac to a Windows network--Jaguar's new tools can't be beat. But home users, beware the $129 upgrade price if you're not looking for networking options.