This is an old issue and I don't know if it's still relevant. The main problem with this issue is that there isn't enough information to understand what happened.

What did you set the path to with Py_SetPath?

The error message says it could not find in "C:/Python33/lib/tcl8.5 .... and so on"

and then you say it works when you set the path in the env to something else:

"set TCL_LIBRARY=C:\Python33\tcl\tcl8.5\"


If you are still having problems with this in a current python version (>= 3.9), please create a new issue with full information on what you did in the program that didn't work.