So, you are wanting to install 2003x64 now, on a 1950 with a SAS 6/iR (from your other thread)? This is the driver you need (found by going to support.dell.com, entering Service Tag or choosing model number), changing OS to 2003 x64: [URL]    
Hello All,  I got some help on the forum about a similar issue with the PE1950 getting it to work with the 32Bit Win2003r2 OS.  I used nLite, added the needed drivers and it's saying the install failed due to it being a 32bit driver. Here is the recommended driver i used to do the 32bit install: SAS-RAID_Driver_FF6F6_WN32_1.28.03.01_A06  I've looked and didn't see the 64bit version, can someone please help me out so I can install this 64bit OS. Thanks!  Prior Thread I got help from: en.community.dell.com/support-forums/servers/f/906/p/19452759/20122580.aspx#20122580
I'm trying to install Windows Server 2003 R2 x64 on a PowerEdge 1950II