Compare Files and Folders
My favorite tool to compare text files (txt, html, php, etc.) is Meld. It gives you a line by line side-by-side comparison. You can easily see the differences and easily copy the changes from one file to the other.
run cmd.exe to get a command prompt. Then do it again, so that you have two of them open next to each other.
in each window go to the directories that you want to compare. (Using 'cd' commands. If you're not comfortable with this, then you should probably go with the external utilities, unless you want to learn command prompt stuff.)
type 'dir /b > A.txt' into one window and 'dir /b > B.txt' into the other. You'll now have two text files that list the contents of each directory. The /b flag means bare, which strips the directory listing down to file names only.
move B.txt into the same folder as A.txt.
type 'fc A.txt B.txt'. The command 'fc' means file compare. This will spit out a list of the differences between the two files, with an extra line of text above and below each difference, so you know where they are. For more options on how the output is formatted, type 'fc /?' at the prompt. You can also pipe the differences into another file by using something like 'fc A.txt B.txt > differences.txt'.