The screen keeps showing lens error. The lens isn't stuck though...

Lens errors are fairly common. Usually it's sand or grit interfering with the lens extension mechanism. Or the camera's been dropped with the lens extended. Or the camera has been powered on, but the lens had been blocked preventing its extension. Or the battery ran down with the lens extended ...Here are some troubleshooting steps that you can try that may (or may not) correct it. They only seem to work for less than 40% of the lens errors, but if the camera is out of warranty (or repair cost approaches that of the camera), they're worth that try. Some of the later steps do involve some risk to the camera, so carefully weigh your options before deciding to conduct them.
And here's a video summary of some of the steps (note that the above link goes into much greater detail):

What you probably have going on here is a "lens error"

A lens error can be caused by physical damage to the mechanism that controls the lens, or debris that is interfering with the operation of the lens.

This article may be able to help you with a "do it yourself" solution.
http://camerarepair.blogspot.com/2007/12/fixing-lens-error-on-digital-camera.html

In the event that your problem is due to physical damage and not just dirt or debris, you will need to take it to a local camera repair shop for troubleshooting-- though with most consumer digital cameras, labor and parts cost of a repair can easily exceed the value of the camera.

Either the camera is having a battery problem, or a lens issue:
Here are a couple sites that explain what you can do to try to correct this:
http://camerarepair.blogspot.com/2007/11/simple-fix-for-dead-cameras-that-wont.html
and:
http://camerarepair.blogspot.com/2007/12/fixing-lens-error-on-digital-camera.html
Even though the article is entitled "lens error", it also applies to stuck lens issues.
Good luck, hope this helps, and thanks for using FixYa.

Dvd disk error and check disk error both are same error.The name is different.In both cases the lens in the dvd unit needs to be checked.The lens is either moved from its position or getting blocked by any dust or any dirty stuff got stuck up on the thin lens glass internally.
In some cases the lens is cracked so the lens assembly needs replacement.But first try cleaning the lens with a dry tissue.You can also try blowing air from air blower first.Blow air in the unit where the disk is inserted/placed.Then check.If still same then the unit needs to be removed out to disassemble to clean the lens manually and also this will help to know if lens is cracked or faulty.

Thanks. keep updated for any more query.you can rate this solution and show your appreciation.

If the lens is stuck then you can try to rotate it manually a little bit but do not apply force this may damage the lens or else it will be better to take the cam to any shop it is 5 min job.

Try jiggling the lens. Use compressed air to blow out any grit around the lens barrel. If that doesn't do it, you'll need to get the camera serviced.

just take out the battery ....charge it ...and put it back....switch off and switch on the camera once....should work fine

There are several causes for this to happen.
1. The lens assy is out of alignment and stuck; stalling the motor.
2. The motor itself is defect
3. If you can hear the motor working , then it will be a stripped plastic gear between motor drive and lens assy.
DIY repair not recommended (possible)

The E18 error is an error message on Canon digital cameras. The E18 error occurs when anything prevents the zoom lens from properly extending or retracting.[1] The error has become notorious in the Canon user community as it can completely disable the camera, requiring expensive repairs.
A quick internet search for "E18" + "canon" quickly reveals hundreds of similar complaints.
ConsumerAffairs.com reports that the "lens has a feature called bellows claw, which is a gear that physically extends and retracts the lens. A piece that holds the lens, the barrier plate, is not large enough and can sometimes cause the bellows claw to malfunction, resulting in a stuck lens". The result is a black screen that only contains the error message, E18. Another problem mentioned on the site blames a sticky iris in the lens, caused by grease entering inside from the microphones built into the lens. The buildup freezes up the ability of the lens to open.

The lens probably has some dirt or grime stuck in the lens motor. If you can gently twist the lens back and forth, maybe with some air.

I have answered this in another post. Here is the link.

If this helps you, please return and choose FixYa! ThankYa!