Almost certainly it's a hardware issue - a vital hardware device is probably faulty.
Start the troubleshooting process by testing the hard drive with the manufacturer's diagnostic software for DOS which loads from a bootable CD and is downloaded as an ISO CD-image file. The links are here: http://www.tacktech.com/display.cfm?ttid=287
You can create the CD from the downloaded ISO file by using IMGBurn
When you've made the CD, boot your faulty Asus laptop from it.
If the hard drive passes the test you should then test the RAM modules with Memtest86+
That, too, loads from a bootable CD so the procedure for creating and using the CD is the same as for the hard drive test. Test each RAM module separately with three passes of the test routine on each one. Then if errors appear you will know which, if any, module is faulty.