Trouble with loading Debian on a server

I have a Dell PowerEdge 1800 and whenever I try to install Debian it skips booting from my USB and simply boots into Windows Server 2003. When I disable all other boot devices from the BIOS it reports that no bootable device is found. The USB works on other computers, just not the server. Ideas on how to get it to run properly? Sincerly, Breadpudding.