I've finally upgraded the computer that is part of my Winlink 2000 station. I bought it from Amazon as a refurbished mini-tower with Win 10 for less than $150 US shipped to my house. I'm now running:
Dell Optiplex 755 mini-tower
Intel Core Duo 2 CPU (E8400) @ 3.00 GHz x 2
8 GB RAM
Windows 10 Home 64-bit version
Dedicated SIIG dual serial port PCI card, so I don't have to use USB-to-serial converters