I have a basic Windows batch script comparing hashes of two files spitting out hashes that don't exist in both txt files.

First it generates a clean file without headers and ignores misc files like Thumbs.db or desktop.ini and stores them in "#_file1_clean.txt", "#_file2_clean.txt". This works great.

Then I use that clean file to generate a log file containing ONLY the hashes. This is where the issue lies, simply from ECHO %%b>>logfile.txt statement, it occasionally throws a "The process cannot access the file because it is being used by another process." error.

Then I use the findstr command to output lines that don't match. This works fine.

Here's the code:

@ECHO OFF
SET "batchpath=%~dp0"
CD /D "