Samidn,  The issue is that on an OS install the driver for the controller must be loaded to see the drives installed on it. With 2008, the driver file should be on the media itself, so you should be able to boot directly to the media. With 2003, there is a couple ways of doing this. You can boot this disk and it will walk you through it - [URL]# Or you can use this driver file directly at the "Press F6 to load 3rd party SCSI/Raid driver"  screen on the OS media - [URL]#  Let me know how it goes. 
I got couple of PowerEdge 1950, trying to install Windows Server 2003 / 2008They came with no HDD in them, and i don't have any SAS, so i insreted SATA (Tried with both Seagate 1TB, WD 500GB only) on nr1 slot But OS can't find any hard drives, I went on BIOS, disabled / enabled RAID with no help, on SATA Mode i can only pick ATA Mode / OFF no more, tried both options,  still OS can't find any hard drives, i went into "Perc 5/i Integrated Bios configuration Utility" Physical Disks and there is my HDD,  Vendor ATA it says, i even made Virtual Disk with RAID0 (Couldn't select any other RAID level) Init it, still OS can't find any hard drives. What am i missing here?  I would really appreciate your help,  Thanks in advance!
WS 2003 Hard drive not found - SATA