Hi Mary,

I'm sorry to hear that you're having trouble resizing your Excel workbook window. Here are a few things you can try to restore the resize functionality:

1. Check if the workbook is maximized: Sometimes, the workbook window can be maximized without the user realizing it. To check if this is the case, hover your mouse over the top of the Excel window until the cursor changes to a double-headed arrow. Then, click on the arrow to restore the window to its original size.
   
2. Use the keyboard shortcut: You can also try using the keyboard shortcut to restore the window size. Press the "Windows" key and the "Left" or "Right" arrow key to snap the window to the left or right side of the screen. Then, use the same keyboard shortcut to snap it back to its original size.
   
3. Reset the Excel window size: If the above steps don't work, you can try resetting the Excel window size. First, close all Excel workbooks. Then, press the "Windows" key and the "R" key to open the Run dialog box. Type "
   Formula:

   excel.exe /s 

   " (without the quotes) and press Enter. This will open Excel in Safe Mode. Open the workbook that you're having trouble with and resize the window to your desired size. Then, close Excel and reopen it normally. The window size should be restored.

I hope one of these solutions works for you. Let me know if you have any other questions or concerns!