File integrity checker

Whenever I install Windows XP, the very first program I install is a file integrity checker. I take the snapshot of the entire drive including all the system files and store the hash file in a CD or USB stick. I can compare this value at any given time to identify the changes on my machine.

There are many open source tools available to do this but I like the MD5summer program http://sourceforge.net/projects/md5summer/

It lets you create MD5 hashes of a folder or all the files in the drive. Once the program recursively hashes the files, it lets you save it as a file.

The program will list some of the “locked” system files that it couldn’t hash.

To test this program, I edited a text file and added “test” to the end, after that I ran the program to verify the hashes of current system snapshot with the saved snapshot.

Sure enough it generated a checksum mismatch for the edited files

It is a good idea to deselect the browser folders so that the history, cookies and bookmark files doesn’t trip the checksum mismatches