BIOS Problems

My BIOS is seeing both of my optical drives as CD-ROM whereas one of them is DVD-RW. When I look deeper into the BIOS disks configuration it lists the DVD-RW but it shows Master drive as CD-ROM and Secondary drive as CD-ROM when in fact it is the Secondary drive that is the DVD-RW and in fact the BIOS knows that because when I ask it for information on the drive it gives it correctly.

I need to sort this out because I cannot install W7 without removing this conflict because I cannot get my machine to boot up from DVD.

My system is a Dell 8300 and I have just updated the BIOS to version AO7 with no effect.

BIOSTech Support Guy System Info Utility version 1.0.0.2
OS Version: Microsoft Windows XP Home Edition, Service Pack 3, 32 bit
Processor: Intel(R) Pentium(R) 4 CPU 3.00GHz, x86 Family 15 Model 3 Stepping 3
Processor Count: 1
RAM: 1022 Mb
Graphics Card: NVIDIA GeForce FX 5200, 128 Mb
Hard Drives: C: Total - 114392 MB, Free - 83628 MB; F: Total - 46 MB, Free - 46 MB; G: Total - 28615 MB, Free - 24360 MB;
Motherboard: Dell Computer Corp., 0W2562
Antivirus: AVG Anti-Virus Free Edition 2013, Updated: Yes, On-Demand Scanner: Enabled

I notice the System info utility log above doesn't enev list either of the optical dtives.

Can anyone help me, please...........