excel 2007 - HELP compare two database but no know how to do it

Hi and welcome to the forum

Depending on the layout of your data, vlookup or index/match will let you compare the 2 sets of data, and tell you that, for instance A1 in data set 1 is in data set 2, and it cannot find A2 in data sat 1, in data set 2. Once we have that, we can start pulling in the missing data.

No need to email the data, as long as it is non-sensitive, you can upload a sample to the forum. If the data is sensitive, maybe you can put some dummy data together for us and upload that instead?

To attach a file to your post,
click advanced (next to quick post),
scroll down until you see "manage file",
click that and select "add files" (top right corner).
click "select files" find your file, click "open" click "upload" click 'done" bottom right. click "submit reply"

Once the upload is completed the file name will appear below the input boxes in this window.
You can then close the window to return to the new post screen.