Given that Katie and Julie use both machines, I am unhappy with the idea of being in a position where security updates are about to be few and far between. I've contemplated trying to update the aged boxes so that I could upgrade them to Windows 10 and have concluded that I could spend a lot of time and money on this project. And the existing machines are five or six years old anyway and were not state of the art when I got them.
So it's time to buy new computers. Happily, I've found an Asus mini-tower that will do the job nicely and is arguably faster and better than my machine in the office. Although the form factor is a little bigger than Gretchen had hoped for -- she'd wanted to find slimlines -- these machines are faster than the similarly priced slimlines, likely easier to maintain, and have a VGA output that the newer slimlines lack, which means that I can plug them into the existing monitors without a lot of grief or adapters. And they have built-in Wi-fi connectivity, allowing me to dispense with the fragile dongles that we're using now.
While George Washington's computer will -- with luck! -- continue running for a while longer, the rest of the family is getting an upgrade. :)