You may need access to Lotus 1-2-3 files while you only have Excel to view them. You can convert the Lotus files easily by opening them in Excel and saving them with the XLS format. However, problems do arise. For example, WK1 files keep their formatting in a file separate from the data.
Confirm that both the data and the format file for the WK1 file are in the same folder.
Open the Excel "File" drop-down menu. Click "Open." Find and open the WK1 file in the folder tree. Don't open the formatting file yourself, just the file with the WK1 extension.
Open the "File" drop-down menu again. Click "Save." Select .XLS as the file type in the Save panel. Select "OK." Excel then converts the workbook into the Excel format.
Open the converted .XLS file to check for errors. Search for the phrase "formula failed to convert." If Excel was not able to convert a formula, it defaults to displaying the value that the formula produced and writes "formula failed" in a cell comment. To search the comments for this phrase, open the Edit drop-down menu and click following sequence: "Find > Look in: Comments." Recreate the lost formulas where possible.
Print out the new spreadsheets and compare the numbers with printouts of the original Lotus workbook spreadsheets, if they are available. This is an additional check to make sure the conversion was performed correctly.
Sometimes, Step 2 results in the error message, “Cannot Open Lotus 123 file.” Unfortunately, this can occur for a number of reasons. You might not have the latest compatibility pack, which you can download from Microsoft (see link under References below). There might be a macro in the WK1 file, which you can have the original author delete.