your motherboard asking you to update BIOS.
1. Download the latest BIOS version
2. Format your USB key in FAT32
3. Unzip your BIOS zip file
4. Rename the file P5G803.ROM
5. Plug your USB key on your computer and he will update your BIOS.
Download link latest BIOShttp://www.asus.com/Motherboards/Intel_Socket_775/P5G41TM_LX/#download
If you can access your BIOS, load default of it.