Desktop icon content incorrect

My desktop icons aren't showing the correct content - when I open one, it shows the content for another. I'm using OSX Mavericks. This is a recent issue. I have rebooted but no change. Please, how do I fix this?

Try doing a shutdown instead - wait 40 seconds and boot up into Safe Boot Mode. Hold down the shift key only when you hear the boot sound.

Login and run Disk Utility (Utilities folder) and Repair Permissions and Verify disk and then restart normally.

If that doesn't fix your problem, try doing an SMC and PRAM Reset.
Intel-based Macs: Resetting the System Management Controller (SMC)

Have you tried cleaning your desktop? You may well have icons on top of other icons, and really you should not have ANY icons on your desktop other than the hard drive itself (and perhaps a few aliases, at best).

Many thanks, the shutdown etc worked.

I don't have much on my desktop and was maybe wrong in describing them as icons - I mean folders, screenshots (which default to store on the desktop) and documents such as user manuals.