I realize this is a rather old topic, but maybe my my experience will help someone.
I started using TurboCAD 14 with WinXP and it worked fine. When I upgraded to Win7 (64 bit) TurboCAD 14 installed and ran just fine. I only recently upgraded again to Win10. I installed TurboCAD 14 and, lo and behold, it installed (apparently). However, I've experienced problems very similar to everyone else above. Particularly, when trying to open older cad files; it won't do it without corrupting them. Tried running Turbocad in WinXP and Win7 modes; no good. I should have, but didn't try creating a new file. Like William_NZ, I loaded virtual machine software (VirtualBox) and then installed WinXP in it and then loaded TC14 (I always liked XP best anyway). It works beautifully.
By the way, I did send an email to Tech Support about this and they replied, without elaboration, that TC14 is only compatible with XP and Win7. The first version to be compatible with Win10 is 2015. So, if you can't or don't want to revert back to XP or 7 OS and you don't want to pay for a TC upgrade, give some virtual machine software a try. VirtualBox is free. Not sure about VMware. They are generally pretty easy to set up. You might have to do a little reading to understand some of the finer points.
Hope this helps