One disadvantage of Microsoft Excel is that users cannot enter numbers starting with "0" unless the field of the cell is changed from a number to text. Macros and other mini programs written into Microsoft Excel spreadsheets are prone to virus infections.
When a data file is too large, it can make the Excel program run very slowly, especially if all of the data is on one file. Trying to break the data down into smaller files can lead to some of it being lost or misplaced. Despite training manuals on how to use Excel, many people still do not find the program user-friendly. The application rounds off very large numbers using imprecise calculations, which compromises complete accuracy.