When you see all xxxxxx's in a cell in Microsoft Excel, it means that the content of the cell is too wide to fit within the column width. This is also known as the "#####" error.

To fix this issue, you can try one of the following solutions:

1. Adjust the column width: Hover your mouse over the column header until the cursor changes to a double arrow. Then, click and drag the column boundary to the right until the content is visible.
2. Change the font size: If adjusting the column width doesn't work, you can try reducing the font size of the cell contents. Select the cell(s) with the xxxxxx's and then click on the "Home" tab in the ribbon. In the "Font" group, click on the drop-down menu next to the font size and select a smaller size.
3. Wrap the text: If the content of the cell is a long sentence or paragraph, you can try wrapping the text within the cell. Select the cell(s) with the xxxxxx's and then click on the "Home" tab in the ribbon. In the "Alignment" group, click on the "Wrap Text" button.