TECH~SENSE! 
*** PC Operating Systems ***

# - Obsolete systems
% - at end of its run
MICROSOFT
MS-Dos #
Windows 3.1 #
Windows NT #
Windows NT 4 #
Windows 2000
Windows 95 #
 #
Windows Millennium #
Windows XP %
Windows Vista
Windows 7
Windows 8 (future)
OTHER (PC)
LINUX
Unix
MAC (many)
   On the left are links about the various Microsoft operating systems, from MS Dos through Windows 7. They provide information and history via Wikipedia.Org. The first seven listed are obsolete and will not work on modern hardware.  After Windows 3.1, came Windows NT which is the system that spawned what we have today (early 90's). NT was not really used in home computers; it was more of a lab and business version. The first for the home was Windows 95 followed by 98 and Millennium. Windows NT, 95, 98, Millennium are the precursor to what we use today.

   NT stands for "New Technology" and still appears within the specifications for XP and newer. Windows 2000 was more of a business or commercial version and included the early enterprise server versions. Most of us usually don't deal with the server environment. For the average user, the sequence was 95, 98, Millennium, XP, Vista and now Windows 7. (Windows 8 is due to be released in 2012 or 2013.) Anyone using a machine that came with Vista installed, should consider Windows 7. It solves most of the problems of Vista, is faster and fully supported by Microsoft. XP is on the way out as far as support is concerned and Vista will most likely disappear faster, considering its poor track record. Business environments have stayed away from Vista for the most part.

   Some early Vista machines may not be upgradeable to Windows 7, at least by those who may be unsure of their technical prowess. Any new machine from the last two or three  years should work. Machines you buy today will come with Windows 7 Home Premium. (The author has upgraded several machines to "7" from both XP and Vista that in theory did not meet the requirements.) Upgrading from Vista to Windows 7 can be done in place, meaning a direct  upgrade, keeping your original settings and installed software wherever possible. Upgrading from XP or 2000 will require (for now) a fresh install. Microsoft has indicated that  Windows 8 will install on all Vista and Windows 7 as an upgrade or fresh install. We shall see.

Note from Microsoft: "Windows XP Support and End of Sales -- Even though we ended the sale of Windows XP on October 22, 2010, we still plan to provide support for
individual users and businesses until April 2014."