Trying to read back a EPM7064STI44 part with Intel stand alone programming software V18.1

The CHECKSUM is not the same as the USERCODE. The default USERCODE in the device, if not explicitly set by the user during programming, is 0x0000FFFF.

If you can only run Win10 then you might consider looking at using VirtualBox, VMware, etc virtual cpu environment to run the old tools in a virtual machine.

This would require setting up a compatible operating system (Windows XP or Windows 7 or maybe even MSDOS) in your VM and then loading the MaxPlusII software.

If you can't run a real physical machine with an old compatible OS nor use a virtual machine then you are basically SOL.