- Open Excel.
- Select "File" then "Open". Make sure you show all file types, not just excel file types
- Select the .txt file, then click "Open".
- Excel will walk you through a Text Import Wizard that lets you determine how the file is delimited and what each column is to be viewed as.
- This will look slightly different in different versions of Excel, but in most cases you will just select "Next".
Click "Next" again on step 2.
- Highlight all columns holding shift down and selecting them all.
- Click the "Text" bubble under "Column data format".
- Click "Finish".
The .txt file will open in Excel while retaining the leading zeros.