Need help with finding the right drivers for Win 7 on Dell Poweredge 1800 server

I have an old Dell Poweredge 1800 that has been completely wiped. I have tried loading Ubuntu Server and a trial of Windows Server 2008 but couldn't get them to work, so I put in a Windows 7 disc that I had and was able to load up. I'm able to get to the Windows 7 installation interface where it says "Where do you want to install Windows" and it shows none of the 4 SCSI drives that I have (in raid 5). So I click "Load Driver" and it says I need to put the drives onto a USB and then try again. I navigate to the Dell website and it gives me a whole list of drivers for my server for my OS and I put them on my USB. I put the USB in and it reads none of the drivers that are on the USB as compatible. I have no idea where to go from here. Also my BIOS version is A06. Please help me, and thank you.