Normally you can hide or unhide workbook one by one in Excel, but there is no way for you to hide or unhide multiple workbooks at one time. For example, you open multiple workbooks in Excel, and you want to handle them one after one, so you may want to hide the inactive workbooks to stay working on one workbook. You cannot hide all inactive workbooks with one click in Excel, but with this Hide Inactive Windows tool of Kutools for Excel, you can:

• Method 1: Hide workbooks in one click (with Kutools for Excel).
• Method 2: Hide workbooks one by one (with build-in function of Excel)

Note: "Hide Inactive Windows" supports Undo, you can quickly unhide all workbooks by pressing Undo (or Ctrl+Z) immediately, and Undo is one level. You can also apply “Unhide All Windows” of Show / Hide to unhide all hidden workbooks.