I've downloaded the Floor Estimate Pro and indeed, it refuses to work saying the software has expired, but here is a quick tweak to get back to your favorite application.
Double click the clock in the system tray and set the year to 2000 and then run the software. It should open properly this time.
Be aware that some apps and websites won't work if you keep the clock to year 2000. Switch it back as soon as you finish working in Floor Estimate Pro.
Also, the software is compatible with Windows 10 64bit as I had no issue running it.