There are several paths where WiredTiger removes files in the WiredTiger namespace that are vulnerable to access errors if that Windows system has some other process accessing the files. It isn't OK that other processes interfere with files in the database directory, but our automated testing sometimes races when shutting down and cleaning up, so having a bit more leniency is helpful. This has led to several false-positive failures if those tests interfere with WiredTiger.
WT-3904 we added code to retry log archiving on an access error of this nature. However, there are other times when other files are removed that remain vulnerable to this.
We should consider moving the retry code from conn_log.c:__log_server to os_win/os_fs.c:__win_fs_remove.