

I suggest googling something like "older autocad on windows 10" or things like that. Some people have gotten it to work with various tweaks. Autodesk will never go back and make a product that old work with windows 10 so you might not have another option besides using an older version of windows or a newer autocad version. Rolling back an update doesn't always fix it either. Sometimes you can roll back an update to windows and get it working again but since it seems like it's a fresh windows install that option won't work for you.

Consider yourself lucky that you kept it working this long. It must have something to do with other programs on the computer at the time of updates and how the update changes the registry according to those other programs. It's been different updates for different people.

I know you said you've been using it for a long time on windows 10, but eventually a windows update breaks it from working for everyone. 2005 doesn't have support for windows 10.
