The VIPER program as well as File Assistant Pro are/were amazing. The best software program devleoped as many will tell you is Amazing Labels.
The problem is, Ed who is a brilliant programmer, doesn't work on these full time or the versions would have been many more by now.
Viper was absolutely the quickest and accurate way to enter vaccines developed. F. A. P is still basically rock solid but needs the Win 11 updates. And, Amazing Labels, well, it has saved us multiple times with getting labs trashed.
I will talk to Ed. Meanwhile, shoot me an email and let me know your problems. I just installed it on Windows 11 Pro no problem. You may also be able to install it on the virtual machine you can make on Windows 11 and run it there.