Uninstall all of the ASUS motherbard drivers you have installed and the Realtek drivers and we'll do this from scratch to make sure you've got everything you should installed in the order it should be.
ASUS support and drivers for M2N-SLI Deluxe:
Download the following and install them in the same order. Restart as indicated:
(Download them all and save them to a convenient location before you start. It will make it easier.)
1. Chipset -> Nvidia Chipset Driver Package V9.19
2. RESTART
3. Chipset -> Make Nvidia 32bit SATA RAID Driver (if needed)
4. IDE -> Nvidia Chipset Driver Program V4.5.2.0
5. RESTART
6. USB -> USB 2.0 Driver for Windows 2000/XP/XP MCE
7. Audio -> SoundMAX ADI1988 Audio Driver V5.10.1.6110
8. RESTART
9. Utilities -> Microsoft Windows 2000/XP/2003 HD Audio Patch KB888111
10. RESTART
Do each and every one and it should work properly. Don't forget to remove any drivers you have already installed as attempting to install over them may cause issues. If you follow every step, you should have everything installed to make your motherboard and its on-board devices function properly.
