this 2007 year PC OLD, has many limits (CORE 2 is one)
is this windows 10? 64bit> I bet not its CORE 2 old)
I came with VISTA if MS loaded OS, or XP or RedHat Linux?
what boot menu are you talking about.? F12?
wild guess me, VISTA OS: (now zero support)
in windows, we have disk manager, do all devices show up now?
this is first, if not here, explorer can not work.
lets do the correct order:
1: bios sees my media. (good)
2: then in device manager, it sees them, if not drivers bad.
3: then Diskmanager sees the devices, and must have drive letter or next. if letters missing right click device and add one.
4: explorer (This PC) fails to find it. if above fails sure.
easy as 1,2,3,4 order, matters.
can't see CD does that mean a disk or the whole drive?
cant See HDD, is this HDD0 ,1,2, 3 or?
how many HDD do you have, and are there SSD drives there
and last what SATA ports are you using, some are limited.
here is your DELL.com support page, (12 years later still here)
https://www.dell.com/support/home/us/en/04/product-support/product/precision-t7400/drivers
what HDD fails,
does the PC boot at all? my wild guess NO.
what OS
what OS do you want to run, that be first thing to ask on any 2007 old PC, as Windows 10 will fail here. I Bet. for sure 64bit.