Any ideas ?
Yes, as papa says,,,, you need to reset BIOS to 133 FSB.
By default, if your system hangs, your BIOS will reset to the 100 MHz FSB, so that overclockers who go to far have a system that will boot.
So, sometimes when Windows fails a boot, or your system just hangs at boot up, then the system will just enter BIOS. That is where most people panic, and just exit the BIOS, (AND SAVING), and saving at the fail-safe / default settings, or the 100 MHz FSB.
So, now your AMD 1000 MHz ( which was 7.5 x 133.3 = 1000) is now running at 750 MHz - or 7.5 x 100.
> Have your mainboard manual ready. Or, download the manual from Asus.
So, on boot up, hit DEL KEY. Enter the section of the BIOS where you set the CPU Speed. Adjust it to 133.
Save & Exit.
1000 MHz again.