I have an acer aspire 5720-4230, turning off automaticly

Try blowing the dust away from the cooler ( look on the sides for the breather ... and sometimes is on the bottom .. ) an you can use any air compressor or compressed air cans.
you gonna thing Im crazy ... but works every time ! :)

tried to remove the battery and then re attached, turn on the pc laptop check if it works.

Is this a new Windows installation? Vist Acer site and install the chipset drivers. Windows 7 does not install these automatically. However Windows 7 can continue upgrading drivers a few days later.
http://www.acer.co.uk/ac/en/GB/content/drivers

Turn off( shut down or restart automatically)?

It maybe cause from overheating from your graphic memory device/harddware or problem with your processor.

Are you have using fan or anyelse to cooldown your laptop during you using it?
Try something, using any fan that can cold and maintain temperature for your laptop to avoid it from overheating. Overheating is not good. It will cause your motherboard problem or screen monitor problem.

if the laptop will automatically turn of mostly the problem is, fan cooler due to clogged with dirt. just open it the back cover, remove fan, clean the dirty with brush thats all.

you pc is in safemode , need to put it back in normal mode , when you start the pc , look at the back screen and read normal mode and move the cursor in to normal mode and click enter you might have 20 seconds to do it

hi try this http://support.acer-euro.com/drivers/notebook/as_5610z.html

It's the scroll lock. Find the Scroll Lock key. To toggle it, press the Function (Fn) key and the Scroll lock key(usually the insert key)

Please rate this a fixya

its in the "performance information and tools" file in the control panel. when i click "rate this computer" link, my laptop will turn off automatically. after that, when i turn it on again, it seem like my laptop becoming unstable. it will turn off anytime it want.