The easy cheap way is to use a Command Window to issue the commands:
DIR directory_n /a/s >textfile_n
for each dir and then compare the textfiles.
Other than that WINDIFF is the way to go.
1999: Freeserve 48K Dial-Up => 2005: Wanadoo 1 Meg BB => 2007: Orange 2 Meg BB => 2008: Orange 8 Meg LLU => 2010: Orange 16 Meg LLU => 2011: Orange 20 Meg WBC