https://bugs.winehq.org/show_bug.cgi?id=52732
--- Comment #11 from Rafał Mużyło galtgendo@o2.pl --- (In reply to Poncer from comment #10 - equivalent exchange, buster)
USER var seems correct, you might still check userdef.reg. Though that should have been an attachment, for one cause bugzilla's wrapping makes some of the lines ambiguous.
Check also 'echo %USERPROFILE%' within 'wine cmd'. Yet, the later values within PATH (those perl derived) look a bit fishy.
(@Zeb: the former comment actually was me being civil; as for whether it is a wine bug or not, it's not completely out of the question, yet given no duplicates for over one release and that bit about python (mess in the environment could fuck python badly in hard to predict ways) seems quite unlikely)