If you want to delete all hidden rows or columns in Excel, just do the following steps:
1. click File tab, and select Info menu from the popup menu list.
2. click Check for Issues button in the Info page. And select Inspect Document from the drop-down list. The Document Inspector dialog box will appear.
3. click Inspect button in the Document Inspector window.
4. click Remove All button in the Hidden Rows and Columns section.