To keep it simple:
If you haven't entered the BIOS menu (by tapping F1 during first part of booting) yourself before this problem occurred,
chances are, you opened an ASUS control menu within Windows, and altered some settings.
This could also have happened through the ATI control catalyst program (or something alike, look for Asus and Ati).
Usually, manufacturers give these settings really fancy names, like "boost", "cruise" or "turbo" for example.
In some cases, it's even possible you entered the settings menu in a game for example, and this in turn has altered some settings in the software provided with your system.
- None needed, your Asus MoBo detected faulty / dangerous settings during boot, and has reset itself to the default settings, probably during the boot you had no lights on your keyboard. The next boot, it asked for "confirmation" from you, and as you pressed F2, all the default settings have been restored again, twice.
- During POST (saying "checking memory -> detecting drives, etc, or when displaying a huge 16-color Asus screen), press F1 and check all settings manually. I'm not sure if you'll understand much of the settings within the menu, so remember, "When in doubt, leave it alone"
- If your in the possession of the driver discs of both the Asus Mobo and the Ati Video Card (AND ONLY THEN!), you could try to uninstall the control centers of your Asus package as well as the Ati graphical card. They are not needed for the OS to work, they are just there to give you the possibility to alter some hard- and software settings, and to mess things up of course Again, when in doubt, do not do this at all. *** DO NOT un-install the DRIVERS though !!!, just the control centers. ***
- I had this exact same issue once on a nVidea GPU after an automatic driver update, it also fixed itself after a second boot.
- OC (OverClocking) can relate to a CPU, RAM, FSB, the GPU and can be done in multiple ways, but is generally not advised for a couple of reasons. In short, the small advantages (20% higher Fps)of a serious OC will result in an instant and definitive loss of warranty, and generally, will shorten the lifespan of the whole system substantially.
So, nothing to worry about ;)