I didn't enter the discussion earlier because I didn't have time to do some research. Oracle Virtual Box is free virtual machine software. It runs on computers with x86 and AMD64/Intel64 processors. If you're thinking of buying an older computer, old Macs are a consideration. I used Virtual Box not long ago when I took the free Harvard online intro to computer science course via EdX. Virtual Box is not too difficult to use.
Oracle VM VirtualBox
There is a version installable on MacOS which permits hosting a Windows virtual machine. The user must provide whatever runs inside the virtual machine. You can buy installable versions of older versions of Windows online from eBay and other sites. I would get the oldest version that runs OrchidWiz, because those will probably be easier to install and configure. You don't need to give the virtual machine network access so security is not much of an issue.