Use o comando comp em cmd.exe
[C:\]comp /?
Compares the contents of two files or sets of files.
COMP [data1] [data2] [/D] [/A] [/L] [/N=number] [/C] [/OFF[LINE]]
data1 Specifies location and name(s) of first file(s) to compare.
data2 Specifies location and name(s) of second files to compare.
/D Displays differences in decimal format.
/A Displays differences in ASCII characters.
/L Displays line numbers for differences.
/N=number Compares only the first specified number of lines in each file.
/C Disregards case of ASCII letters when comparing files.
/OFF[LINE] Do not skip files with offline attribute set.
To compare sets of files, use wildcards in data1 and data2 parameters.