Before you run the troubleshooter, make sure that you back up the registry and all files in startup folders used by Excel so that you can restore the registry and backed-up files if a problem occurs. You need to be on Windows 10 or higher to run the troubleshooter.

Get Help has troubleshooters you can run for many common scenarios. These often help resolve issues without the need to contact support. If a troubleshooter is available for your issue, select Run to start that troubleshooter.

Select the cell or range of cells that you want to add a border around, change the border style on, or remove a border from. The Borders button shows the most recently used border style.

Use the following methods in the order in which they are presented. If you try one of these methods and it does not help, go to the next method. You might have to set Windows Update to automatically download and install recommended updates.

Use the System File Checker tool to repair missing or corrupted system files. When critical Windows system files are missing or corrupted, some Windows features may stop working correctly or Windows may stop responding altogether.

Right-click over the cells you've chosen and select Format Cells and, in the popup window, click the Border tab. For a continuous line, choose one of the thicker styles from the Line box.

Use this tool to find and remove specific prevalent threats and reverse the changes that they made (see Covered malware families). For comprehensive malware detection and removal, consider using Windows Defender Offline or Microsoft Safety Scanner.

Task Manager is an application that serves as a system monitor and startup manager for Windows, providing insights into your device's performance and resource consumption. It allows you to view and manage running applications, assess CPU load, memory usage, disk activity, and network usage.

To change the look of that border line, use the Borders options. In Word, on the Home tab, or in Outlook on the Format Text tab, select the down arrow next to Borders.

After you've selected your text and found the basic type of border you'd like, open the Borders menu again, and choose Borders and Shading. Make your choices for style, color, and width, and then apply the choice with the buttons in the Preview section of the dialog box.