Select the rows above and below the hidden rows
Right-click the selected row headers
Click Unhide
Select the rows around the hidden rows
Go to the Home tab
Click Format
Choose Hide & Unhide
Click Unhide Rows
Select the entire worksheet by clicking the Select All button or pressing Ctrl+A
Go to the Home tab
Click Format
Choose Hide & Unhide
Click Unhide Rows
Select the row headers spanning the hidden rows
Drag the boundary between row numbers to reveal them
Use the Name Box to enter the hidden row range
Press Enter
Unhide the selected rows from the row header menu