I have an extensa 5420-5687. 1 day my laptop just

It seems that your computer needs to have a reinstall of your original setup, because the driver that tells it to shut down is not cooperating. Hopefully you have your original dvd/cd.

The processor has to perform large amount of work while surfing , especially while usingvideos and animationMultiple windows/tabsnumber of browserwhich in turn produces lot of heat . The heat produced is managed by the interneal heat sink and inbuilt cooling fans.But this cooling process may get affected by the blockage in air vents due to dust.So to safeguard the laptop form overheat, it automatically shuts down.
One simple try :Go to the Adobe flash properties and disable Hardware acceleration for online content. That ought to stop the system from rebooting or crashing.

Else...Its better to call a technician when it shuts down often.....

when u turn on your laptop press F8 and hold find the 1 that says last know configuration ok try that

have you enabled "standby"mode,you usually have an option when shutting down.Either this or go into settings and make sure you havent adjusted sleep mode for the screen

Please reinstall the Video Driver and check if the same issue persists. If the issue started within last 90 days, you can try the System Restore

Are you running XP or Vista

The Blue Dump or Blue screen problem is related with RAM.
1. Try by Cleaning the RAM and RAM slot
2. Try changing RAM
3. Also try changing HDD cable

You most likely have a problem with your hard disk. It's possible a virus did some damage, or a power surge interrupted it while it was writing to a critical file. You can try connecting a mouse to one of your USB ports and booting into safe mode to do a virus scan but most likely you will save time and trouble by simply re-installing your operating system and reloading all of your software.

Try the following:
1) Remove power cord, battery and hold the power switch down for at least 30 seconds.
2) Remove and reinstall your memory module(s).

If those don't do it, get back to me for more ideas.
Thanks!
Ron

dear tracy
just boot in safe mode and see how the things are going
(how boot in safe mode
when you switch on your laptop press down f 8 key when the bios screen come then you will get safe mode option just select it with up or down key and hit enter then you follow the instruction)
inform me wht happen in safe mode then i can assit you more