Final answer:
The National Software Reference Library (NSRL) from NIST is the tool that would aid in identifying ordinary operating system or application files.
Step-by-step explanation:
The tool from NIST that would aid in identifying ordinary operating system or application files is the National Software Reference Library (NSRL). The NSRL is a collection of known software and file profiles that can assist in identifying files based on their hash values. By comparing the hash value of a file with the NSRL database, it is possible to determine if the file is a known operating system or application file.