Not sure if this will help, but here is the correct Ethernet driver for the 9020SFF. I have this exact PC. 

Maybe the file got corrupted while transferring to the USB drive? 

I have a Linksys WUSB6300 v2  USB Wireless adapter which works fine, of course, I have Win10 on mine, not sure if it would work on yours in this case.

Thanks for your quick reply.  That exe is one of several I had found, copied to a USB (without properties), and copied to the WHS server.  I got the "not a valid Win32 application" on that one too.  Would you be able to go into device manager and get the file name of the driver you're using?  Also, do you know what the bios setting is for the NIC? On mine, it was initially set to disabled, and I enabled it. Later on the Dell site I saw something that I thought said it needed to include "Pxe" (or something like that - I'm running a backup and can't check now). I may end up just using the wireless adapter but I'd really like to get the ethernet connection working!

Thanks again!

The BIOS setting for the NIC is enabled by default. Enabled with PXe  usually enables it to boot from it. I'm not near my computer at the moment, but I got to thinking...

I have to wonder if it's a compatibility issue with the file driver you're trying to install. What version of WHS did you install? The 9020 originally came out in 2013, with support for Win 7, 8, and 10. Microsoft dropped support of the original WHS in 2013.  WHS 2011 could work with the 9020, but not sure on the original WHS when it comes to all the components. 

"I installed a wireless USB to the 9020 which works, but because this is ancient software, I'm unable to connect to any websites via Internet Explorer to look for drivers."  I think this might be your answer.

I'm not as familiar with the WHS version you may have, but it reminds me of EOL/EOS Win7.  Can't do anything with it without the once supported updates.   It can barely go online.

Have you tried, if possible, transferring drivers with properties?  As long as you can't connect to websites using Explorer, have you tried downloading Chrome or Edge, or won't it do that either?  Just some ideas even if OS is EOS.

Also:  Chrome Sunsetting Support for ol' Windows and Windows Server 

Like Win10, a newer version of Windows Server may already have the drivers you need.  WS 2019 is supported until Jan. 9, 2029.  It's based on the Win10 platform.  WS 2016 is EOS as of Jan. 11, 2022.  Explorer is EOS as of June 15, 2022.

This is the original WHS, but it's been running well on my old Dimension 8400 (shipped to me in 2004!) until recently.  I'll contact the local Ebay store where I got it and ask them about it.  I didn't pay very much for it so I may buy a PCI-E network card and be done with it.  I've spent the better part of two days trying to get this to work.  Thank you for trying to help.

I haven't been able to transfer drivers with properties.  To clarify on the internet access, I can get to Google and do a search but if I click on any links on the mostly text page that's returned I get a "page could not be loaded error".  I've located a chrome download and will try to transfer it to WHS with a usb drive, but I have an initial backup running using WiFi (30 hours so far!) and don't want to mess with anything.  I've also ordered a PCI-E ethernet card with drivers.

I like my ancient WHS but I've had many headaches trying to find drivers while restoring a backup to a new hard drive for a PC.

CBIVTI22, I misinterpreted your earlier comment about when the 9020 came out vs. the age of WHS and realize you meant that it might not be able to run WHS.

I think you're right about getting a PCIe Ethernet card.  I hope it all works out!!  : )