Which version of Windows available today would be the best for using in 30 years time no updates

Windows 10

Windows 10, as you might still be able to get hardware for it that aint broken.

Windows 2000 Pro

not even linux does this. LInux distros typically last 5 years max.

None, all of them are buggy and unless you never use an internet connection it's not gonna last without being pozzed

none

This. As long as you aren't exposed to the internet

This.

agree, 98 is the best.

>As long as you aren't exposed to the internet
Who the hell uses a computer without the internet? It becomes useless then

This.

The long-term compatibility of an OS depends on popularity, which is determined by its perceived quality and its alternatives. XP lasted half of that 30-year period because it's a quality OS, with the only proper alternative being 2000, which MS left behind when XP SP2 was released in 2004. Vista's irrelevant today because we weren't ready for it in 2007 and it was replaced by Windows 7.

7 being just as popular as XP was will likely last just as long. It depends on how different 7 is to 10 or whatever comes in the future. With XP and 7 there were stark differences, and when XP's install base dropped it was left behind so developers could take advantage of newer technologies.

For anyone using Windows 8.1 like me, we're in the same position Vista users were when XP was still commonplace. We should hope that 7 lasts a good few years yet, because once its popularity finally drops, 8.1 will likely get left behind as well due to its low popularity.

It's hard to give an answer to your question because we don't know what the future holds. Things probably won't move as fast as they have in the past 30 years. I imagine the current build of Windows 10 should still be at least somewhat compatible with software 30 years from now.

xp sp1 no fucking doubt about it
aaannd a very strong firewall yes