I used to have a template from someone out here. But now I can't find it!

I have the same table structure on two tabs, but I want to compare the
tables against each other to see where there might be any differences or
duplicates before merging the two sets of records into one. There are a
giolion freeware and shareware links coming up when I google this but the
results are either totally squirrly (two of them tried to restart my Trial
Director instal????) or they give results but the report is SO not user
friendly and will take hours of combing through for clean up.
I have even tried putting each tab in a seperate file. Doesn't seem to
matter.

Does anyone have or can anyone reccomend a tool that will accomplish this?
Thankyou!