Just put together a new PC with an ASUS P4P800-E-Deluxe, WD 250MB 100mbs HDD, ATI Radeon 9600 SE 128MB, 512 MB DDR RAM, and a CD-RW drive. WinXP Pro OS. Pretty basic setup. When I boot up from a cold start I get an error "Reboot and select proper boot device or insert boot media in selected boot device and press a key". If i press a key with a Win XP CD or Startup floppy in the drive it does nothing, even with the BIOS set up to boot from the CD/Floppy or vice versa, and just reverts back to the same error. If I cold start the machine and enter the BIOS, the HD does not show up initiallywith auto detect enabled, but if I open up the auto detect line in the BIOS it shows up. I reboot from there and the machine boots just ine. If I just hit CNTL/ALT/DEL from the boot media error it boots just fine and works 4.0. I have chatted with ASUS on this one and from reading alot of tech forums it seems like a pretty common issue with ASUS MOBOs. I have reseated the cables, cleared the CMOS, changed the CMOS battery(thinking that maybe the CMOS is dumping-ASUS told me to do this as well) to no avail. I have tried putting the HDD on the secondary IDE port to no avail. ASUS seems to be sending me in circles on this one. Is it a 100/133 compatibility issue. If it is why would it boot on the second time around. It seems as if the BIOS is not finding the HD soon enough before it kicks in the error message but with a restart via CNTL/ALT/DEL it keeps the HDD info in there and boots fine. Any ideas?