Windows

Windows 7 prebeta (build 6801)
Although not even in beta, Windows 7 already appears stable and full of consumer-friendly features.

Windows Vista SP1
While it's always good to install the latest code for any operating system, installing the Windows Vista SP1 update will require some casual users to spend a few hours without any visible or tangible improvements to their systems.

Microsoft 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.
Specs: 1 PC, Complete package, 20 GB, Intel x86 1 GHz, 512 MB, DVD-ROM, Sound card, 32 MB video memory, Internet connection, DirectX 9.0 compatible graphics card, Intel x86, 1 GHz

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.
Specs: 1 PC, Complete package, 40 GB, Intel x86 1 GHz, 1 GB, DVD-ROM, Sound card, 128 MB video memory, Internet connection, DirectX 9.0 compatible graphics card, Intel x86, 1 GHz

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.
Specs: 1 PC, Complete package, 40 GB, Intel x86 1 GHz, 1 GB, DVD-ROM, Sound card, 128 MB video memory, Internet connection, DirectX 9.0 compatible graphics card, Intel x86, 1 GHz

Windows Vista Ultimate
Windows Vista 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.
Specs: 1 PC, Complete package, 40 GB, Intel x86 1 GHz, 1 GB, DVD-ROM, Sound card, 128 MB video memory, Internet connection, DirectX 9.0 compatible graphics card, Intel x86, 1 GHz

Microsoft Windows XP SP2
We recommend installing Windows XP SP2 but only after Microsoft has had a few weeks to work out the kinks.
Specs: 1 user, Complete package, 1.5 GB, Intel Pentium 233 MHz, 64 MB, CD-ROM, SVGA monitor, Mouse or compatible device, Intel Pentium, 233 MHz

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.
Specs: 1 server, 5 clients, Complete package

Microsoft Windows XP - Professional
Windows Professional boasts serious corporate administration tools--it's a trustworthy upgrade from Windows 2000.
Specs: 1 user, Complete package, 1.5 GB, Intel Pentium 233 MHz, 64 MB, CD-ROM, SVGA monitor, Mouse or compatible device, Intel Pentium, 233 MHz

Microsoft Windows XP - Home Edition
XP is a worthwhile upgrade from 95/98 or Windows 2000. Unless you need corporate administration tools, XP Home Edition should suffice for most--even for small businesses.
Specs: 1 user, Complete package, 1.5 GB, Intel Pentium 233 MHz, 64 MB, CD-ROM, SVGA monitor, Mouse or compatible device, Intel Pentium, 233 MHz