I like paint shop pro, I use 4.12.

I need to just break down and find an old version of that... from before the Jasc sellout. IIRC, it ran via Wine without issue too.

I try to use Pinta/Paint.Net, but it's not quite as good as I remember psp being. I don't even hate the newer MS Paint... thought I'm only on windows for my work environment and even then.

Aside: I've been using my personal computer more, so I can work on a limited surface with docker and ai agent, then just bring in the components I'm working on when ready. My work environment is really locked down, no wsl, no docker... and it's like working in 2002 to some extent... It's literally easier for me to create stand-alone projects, work on a given feature in complete isolation... AI agent mostly to boilerplate the environment and most of the automated sanity tests, then I can focus on just what I'm working on.

If you don't mind using a browser, Photopea is pretty awesome: https://www.photopea.com/

They also added strange hacked on half-support for alpha-transparency in modern MS Paint. Meaning there is an alpha layer, and imported staff may utilize it, but if you need to do anything with that layer, you're basically SOL.

Better to have no alpha-transparency than whatever this is. At least old Paint just turned it white, and you could manipulate the white layer, with this working with the alpha layer is a nightmare.

Why does it show registry error?

I copied out mspaint.exe and some resource files as well were needed.

It runs for me without error.

No idea. Probably because I'm on a work machine and need admin permission to make registry changes or something