Windows 2003 (32 or 64 bit) doesn't support booting with UEFI. So you'd need to stay in BIOS mode. Also, Windows 2003 doesn't have the PERC driver natively, so you'll need to provide it the driver (via floppy drive (Windows 2003 limitation) or integrate it into a 2003 ISO and burn it again. The 2003 media also needs to have SP2 as part of it.
I've got a Dell PowerEdge R410, to which we were running Windows Server 2003 R2 (32bit) on for about six months.  We were testing a product and we've decided to roll out that new product. The server was built originally, with one giant virtual drive (two 2tb drives combined into a single  raid0 4tb drive).  During that original build, it was set up using UEFI for the install and then BIOS set back to use BIOS as the boot.  Went to wipe out the raid array, built it as two single 2tb raid1 drives (perc 6/h700); however, every time I boot to the Windows CD, I that it cannot find any disks.  Go into UEFI and try that way, and get basically the same thing. I've tried downloading the OM 6.5 Systems Build disk; however, then I run into errors asking for a server manager disk (which I thought was part of cd..guess not). How, can I get this thing going again?   Thanks
Win 2003 R2 on a PE R410