Compare Data Between 2 Worksheets

[BradHart]

I have two worksheets each with 2 columns Block Number and House ID, The first sheet is my master list, the second is assigned units. I would like to have a third sheet that tells what is still available by subtracting anything in the assigned list from the master list. What is the the simplest way to do this with lists containing 60k and 30k rows respectively?


Office 2010

[BradHart]

I'm still interested in trying to do this in Excel alone but I did manage to use a quick and dirty work around. If anyone is interested in it went like this.

1. Paste my master list into a text file twice and the assigned file once, save as tab delimited and close.
2. Import text file into Access.
3. Run duplicate query and export to Excel spreadsheet.
4. Open in Excel. Delete everything with 3 duplicate and keep everything with only 2 dupes.
5. Scratch head, have beer, and wonder why this was so much faster on my slow machine than importing files into Access and running umatched query on fast machine, which still isn't finished.
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