If that doesn't work, try loading the driver at F6 (if system has a floppy or you have a USB floppy - you will need to boot to BIOS while drive is connected and set USB emulation to Floppy in the BIOS).
This driver is from Dell's website and is for XP (as 2003 is not a supported OS on this machine), but the XP drivers usually work for 2003. If not, you can see if Intel has an XP SATA driver for the Q45/ICH10.
http://support.dell.com/support/downloads/download.aspx?c=us&cs=08&l=en&s=bsdr&releaseid=R222843&SystemID=PLX_780&servicetag=&os=WW1&osl=en&deviceid=16825&devlib=0&typecnt=0&vercnt=1&catid=-1&impid=-1&formatcnt=1&libid=41&typeid=-1&dateid=-1&formatid=-1&fileid=318148