I was doing it wrong, and then I remembered the right way. Need a Dell driver? For ANY Dell? For audio, networking, etc? IDT? Sigmatel? Ricoh? Texas Instruments?
Don't go to support.dell.com... GO TO ftp.dell.com.
You'll see a hierarchical list where you can surf down to your machine, and find a list of drivers with their compatible OSes.
Don't know what the device is? Go to device manager, find the device you need the driver for (even if it is "unknown") right-click it, and select "Properties". In the new panel, go to the "Details" tab, and click on the long, undecipherable string (you'll see "VEN/xxxxDEV/xxxx" where xxxx is a hexidecimal number) and hit Ctrl-C to copy the string to your clipboard. Go to your favorite browser and paste (Ctrl-V) the string into a search. This will give you information on the device and manufacturer (plus a lot of "join us to get your drivers!" sites that are spam-riddled cesspools of bad drivers).
Use the manufacturer and device information at ftp.dell.com to find the correct driver for your machine and OS.
The reason "support.dell.com" doesn't always work (even with a support tag) is that it directs you to the most popular drivers for your hardware/OS configuration, NOT necessarily the driver that came with your machine. It searches the ftp site and provides the best match based on OS, then device, THEN machine name, and picks the first driver that matches.
After a long hiatus, I came back to Dell, because they have the resources - you just have to know where to look.
Oh, yeah, if your OS is Linux... well you may be surfing non-free mirrors for a while.