I just had to reinstall windows, but my last winstep backup is from jan 2016...
Is it possible to get the setting files from the windows.old folder?
Where are the settings of Winstep stored?

In the Windows Registry.

HKEY_CURRENT_USER\Software\WinSTEP2000

Oh...

I found out that I can open the registry from the old windows install and export the keys.
I had to import the hive in regedit, export the Winstep2000 key, and then edit the paths afterwards.
But it didn't work - Winstep still loads as it was before the edit.
I've checked the registry and it has been correctly imported.
HKEY_CURRENT_USER\Software\WinSTEP2000 contains entries from recent changes, like the paths to my latest icons.
Shouldn't this work?

It should work, provided you exit Winstep, import the key, then run Winstep.

After exiting Winstep and before importing from the exported file, it would probably be a good idea to delete

HKEY_CURRENT_USER\Software\WinSTEP2000

from the Windows Registry first.

This is because importing MERGES entries. This way you would be sure there is nothing to merge with. Just be VERY careful you don't delete the wrong thing.

This has solved it. Thanks!