Excel is ideal for storing and making calculations based on your data. But unlike Microsoft Access (Excel's sister database program) it does not contain simple tools to allow you to find unmatched or matching data between two spreadsheets.
One way to compare information in two Excel spreadsheets is by using a conditional formula. Create a new Excel file (name it Comparison.xls) and enter "=IF([Spreadsheet1.xls]Sheet1!A1<>[Spreadsheet2.xls]Sheet1!A1,"Different","Same")" into the very first cell. Replace Spreadsheet1.xls and Spreadsheet2.xls with the file location names of the two spreadsheet files you want to compare and Sheet1 with the name of each workbook containing the information. Repeat this same formula in each cell of the spreadsheet but replace "A1" with the corresponding ID for each cell. Whenever you see the word "Different" it will indicate a cell that contains different information and "Same" indicates that the data matches.
You also can purchase and download third-party software utilities to compare information between Excel spreadsheets (see Resources). Make sure you scan any third-party utility that you choose with your anti-virus or anti-spyware program before installing it to your computer.