Some things are annoying by their nature - spam, Jim Davidson, people with massive dogs who say: 'don't worry, he won't hurt you'. But when the annoyances stem from stuff you've paid for, fur starts flying.

Unlike PC Advisor's 20 worst technologies of all time, annoying products aren't necessarily bad. They just make you think bad thoughts.

And they all have one or two traits that make you want to encase them in concrete and toss them off the side of a boat.

From stupid features and rude behaviour to brain-dead design and poor corporate policies, these 20 products have truly annoyed us over the years, and some continue to do so.

This list hardly covers every annoying tech product ever made - MBS didn't make it, for one. So if a product not listed here really got under your skin, please post a comment below. If nothing else, you might feel a little better.

1. AOL CDs (1993 to 2006)

As our number 1 worst product of all time, America Online gave all of us plenty to be irked about over many, many years. But the carpet bombing of free AOL discs was possibly the most annoying (and environmentally irresponsible) marketing campaign ever waged.

Estimates put the number of discs shipped between July 1993 and July 2006 at over 1 billion; we feel like we received that many ourselves.

2. Windows Me (2000)

Windows Me the worst version of Windows ever released. It was a mess. Shortly after its release a tidal wave of bug reports smashed into Redmond. Installation was difficult, hardware driver support was sketchy, and system crashes were routine.

As one analyst said: "If you upgraded to Me from an older version of Windows, you might feel that the term Millennium refers to the length of time it will take to fix the glitches."

3. Apple iTunes, Microsoft Windows Media Player, Microsoft Zune, Napster (2003 to present)

The media players themselves are mostly fine, but their incompatible DRM (digital rights management) schemes drive us nuts. Despite Apple's recent decision to sell some DRM-free songs, most iTunes tunes still play only on iPods, a couple of Motorola phones, or a computer with iTunes software on it. (And the DRM-free songs cost 20p more - or, er, 15p in the States. Another annoyance.)

Windows Media files are worse - now, two different, totally incompatible DRM file formats use the .wma file extension. So if you buy a WMA file from a service that uses Microsoft's PlaysForSure DRM (most notably Napster), it won't work with the Zune (which uses Microsoft's Zune DRM). Can't we all just get along?

Microsoft has said it will "soon" sell DRM-free music for the Zune. We'll see.

4. Intuit Quicken 2005 (2005)

Software companies have two ways to guarantee a software revenue stream: come up with compelling new features that entice users to upgrade each year, or take features away if they don't. Intuit chose the latter path with Quicken 2005, forcing users of older versions to pony up if they wanted to continue downloading data from their financial institutions over the Internet. Intuit QuickBooks 2007 earns a dishonorable mention as well, for forcing users to upgrade if they want to run Windows Vista.

5. Real Networks (Progressive Networks) RealPlayer (1996 to 2004)

Why RealPlayer? Mostly because it had a relentless pushiness about everything it did.

For example, in 1996 Progressive Networks (now called Real Networks) began offering RealPlayer in a pay-for Plus version and a free version, but finding the download link for the free one was like playing "Where's Waldo" on the site. Once you tracked down and installed the free player, it declared itself your default media player for all file formats and began nagging you to pony up for Plus.

Later versions installed themselves into your Windows system tray and popped up pointless (and annoying) "special offers" from Real advertisers. And, of course, Real's notorious attempts to assign unique ID numbers and track consumer media usage - anonymously or otherwise - did nothing to endear itself to us. Pay for this pioneer of pushiness? Get real.