Press the reset switch

Open DVR cover then locate a micro switch in Main Board.
when DVR switched off keep pressing this switch and then turn on the DVR.
keep switch pressed until you hear 3 or 4 beeps.
or a message appear on screen.
Resetting to the Factory Defaults.

the switch in the SD card 'socket' that detects the lock is probably broken

This alarm indicates that AN IRREGULARITY IN THE MECHANISM OF THE CAMCORDER HAS BEEN DETECTED.You can solve the problem by hitting the reset button.
Resetting procedure is described below.Your feedback would be appreciated.Good Luck.

The enter button must be pressed and held down momentarily. It's as if the processor in the camera is not only slow but stupid. Put in a digit, press enter and hold down for 1 second, release. It should take everything if you do it slowly.

Hope it helps.

I found the fix. It's so easy.
Take out the battery
When it says hit the reset button, hit the reset button.
Turn the camera to off
Take out the battery
Wait 2 minutes
Put the battery back in.
Turn on the camera. It won't say reset anymore.

ok try this pls take out the mem stick b4 going fwd

factory reset the camera

Home Screen>Settings>Main Settings1>Initialize press OK on Control Button and then OK select Initialize All Settings press OK

then pls turn off the camera and take out the battery then move power switch of camera to ON position for 1 minute

after 1 minute move power switch to OFF position and then put the battery back and see everrything is OK

pls let me know with the results

Rate me FIXYA if i fixed ur problem

hmm...maybe:
You need to know in which position was camera turned of.
So try turning it on in RECORD OR PLAY position.
It will work then...

Try resetting to factory settings - here's how

• Firstly press the 'menu' button, then the up button above the 'OK' as many times as needed, until you see the top folders are highlighted.
  
  
• Press the right button near the 'OK' until you see the last folder highlighted. You will know this is highlighted when you see the first menu option that says 'Language'. The 3rd one down from that says 'Clear Settings'.
  
  
• Press the down button under the 'OK' until 'Clear Settings' is highlighted, then press the 'OK' button.
  
  
• Scroll up to your choice and press 'OK' to reset your Canon 400D back to default factory settings.

Now try - it could have fixed it. If not, keep turning the dial back and forth, and see if it jogs the camera's operating system. Try switching on and off. You should know, by the way, that the on/off switch doesn't really switch the power off - it tells the internal computer chips that you want the camera to switch off, and then the program closes it down enough to not respond until you either switch it on again, or take the battery out and re-insert it, when it will indicate a red light on the back of the camera to show the battery has made connection, then you switch on again; good luck - if not, phone Canon in your area

remove battery for a while .put it again and try .if not works...remove battery agin then put it again by keeping power switch off. eject and remove cassette .take several eject operations. now try again.

no solution as yet mine did exactly the same and i lost all of my information on the disc. Suggest remove battery and open in record mode, camcorder will say error with information and ask if you like to repair disc, press yes and continue as normal!