mark ramritu, there are a couple of things that can cause this error. It is possibly due to the BIOS trying to boot from the network card. Enter your BIOS and change the boot order to either fixed drive or CD and see what you get. The other possibility is that your hard drive has failed and the BIOS is trying to access the next boot device. Check to see if your hard drive shows up in your BIOS. Change the boot order to CD and see if your computer starts up with a boot CD. Of course you also want to make sure that your hard drive is properly seated. the other thing you could try it to "hard reset" your ACER:"
1. Remove battery.
2. Remove AC power.
3. Remove and reseat your RAM modules.
4. Replace your RAM modules.
5. Hold down your power button for 1 minute.
6. Replace your AC power (not battery) and turn on.
Hope this helps, good luck.