laptop infinite rebooting on startup

[luda100ka]

Hello, last night my laptop was doing fine and I try to boot it now and it shuts down and reboots. And it keeps doing it endlessly. It gets to screen where it says "press f2 to enter setup, press f12 to change boot device". I try to press it but it doesn't work and if I press more buttons it does this anoying beeeeeep sound and shuts down as it would without pressing anything. Then it restarts, gets to the screen, shuts down and all over.. I dunno what to do, was cool last night.

 

[KC2049]

If you are not able to get into the bios it could be something with your motherboard.
What kind of laptop do you have?

 

[boosted1g]

What is laptop model and what version of windows?

Do you ever get to the Windows splash screen?

Do you have any flash drive or external hard drive plugged into the laptop? Is there a CD in the tray?

 

[luda100ka]

I have an acer aspire 5742-6682.
No CD or external drives connected. Can't press anything..and it's just one beep.

 

[boosted1g]

Short beep, long beep, or continuous beep?

 

[boosted1g]

What version of windows and do you ever see the windows splash screen (saying welcome or starting windows)?

 

[luda100ka]

Its not very long beep. Ive got windows 7 and no, it just gets to black screen with white letters on startup and there it turns off.