In addition to which, Dave Barry lists the versions of Windows that he has encountered:

Windows 3.1, Windows 3.11, Windows 3.111, Windows for Workgroups, Windows for Groups That Mainly Just Screw Around, Windows for Repeat Offenders, Lo-Fat Windows, The Artist Formerly Known As Windows, Windows 2.0, Windows 3.0, Windows 3.1415926, Windows 95, Windows 98, Windows ME, Windows RSVP, The Best of Windows, Windows Strikes Back, Windows Does Dallas, and Windows Let's All Buy Bill Gates a House the Size of Vermont.

In the real world, if you have a computer made after, say, 2002, you're almost certainly running one of these versions of Windows:

• Windows XP (released in 2001)
• Windows Vista (released in 2006)
• Windows 7 (released in 2009)

And each of these versions of Windows can be further divided into sub-versions (usually called "Editions"), of which the most common types are:

• Windows XP: Windows XP Home, Windows XP Professional, Windows XP Media Center Edition
• Windows Vista: Windows Vista Home Premium, Windows Vista Business Edition, Windows Vista Ultimate Edition
• Windows 7: Windows 7 Home Premium, Windows 7 Professional, and Windows 7 Ultimate Edition

And then even within these categories, the specific version of Windows can be divided into further sub-versions based on which "Service Pack" has been installed:

• Windows XP Professional "Gold" ("Gold" is often used for a particular edition of Windows without any Service Packs installed)
• Windows XP Professional Service Pack 1
• Windows XP Professional Service Pack 2
• Windows XP Professional Service Pack 3
• And similarly, different service packs for other editions of Windows

What makes a "service pack" different from other types of "version" differences, is that service packs are released by Microsoft for free. For Windows XP (all editions), the latest service pack is Service Pack 3; if you're running any version of XP Professional other than Service Pack 3, Microsoft recommends going to their website and downloading Service Pack 3 and installing it. (Of course, what they really recommend is going out and buying Windows 7, but that costs money.)

So, what version of Windows do you have? Well the salesperson would have told you when you first purchased the computer, unless you installed a new version of Windows on the PC since then, but maybe you forgot, which is why you're looking at this Web page. Don't be embarrassed; we can't see out the other way.

So, on some Windows installations, you can see the Windows version just by clicking the Start button in the lower-left corner of the screen:

But the version isn't always displayed on the Start Menu, and besides, that won't tell you whether you're running Service Pack 1, 2 or 3, etc., and if someone is helping you solve a Windows problem, they'll often want to know what Service Pack you're running.

To find out what version of Windows you're running, hold down the Windows key on your keyboard (it's usually in the lower-left corner of the keyboard, between the "Ctrl" and "Alt" keys, with the little squiggly Windows logo on it) and while holding down the Windows key, press the R key. That will open a Run dialog:

In that dialog, type "sysdm.cpl" and hit Enter. That will open the System Properties dialog box:

Circled in the picture above is the information that you're looking for, if you want to know "what version of Windows" you're running: Windows XP Media Center Edition, Service Pack 3. If technical support is helping you out with a Windows problem, and they want to know what version of Windows you're running, that's what they're asking about.

Bennett Haselton is a technology and political blogger who knows everything, including how to bypass the LightSpeed/Total Traffic Control Internet filter.