According to the aforementioned bug report, we should also add a test for e.winerror == 5. Chances are that other cases will arise one day or another... Since the purpose of the test is, allegedly, to "Verify that an open file can be stat'ed", it may be simpler to create and open a file ourselves (test_support.TESTFN being an obvious candidate :-)), and check that it can be stat'ed. Expecting to be able to access C:\pagefile.sys sounds as "right" as doing the same with, say, /etc/passwd under Linux. (and, incidentally, creating the file ourselves means the test will stop being Windows-specific)