Hi mjn2736,

Welcome to the Community.

I understand your concern with regards to the Monitor.

As you have mentioned that you are an error message that says cannot display this video mode, try following steps:

Check if you are able to boot the computer in safe mode then try to do system restore to last working day when the computer was working. To go in safe mode you need

• Turn the computer on or restart your computer by pressing the button on the system tower.
• Start tapping the F8 key as soon as the computer is turned on. The Windows Advanced Boot Options Menu should appears. If you begin tapping the F8 key too soon, some computers display a "keyboard error" message. To resolve this, restart the computer and try again.
• Ensure that the Safe mode option is selected.
• Press Enter. The computer then begins to start in Safe mode.

Then try to change the refresh rate for the monitor from by going to

Right click on an empty space on the desktop and click on Screen Resolution

Select the monitor Display you want to change the screen refresh rate for

Click on the Monitor tab. (See screenshot below)

B) Select an available Screen refresh rate from the drop down menu.

C) Click on OK.

Click on Yes to confirm the screen refresh rate change

Click on OK

Then restart the computer and check if the issue is resolved if not a in safe mode once again and then tried to follow the instructions for system restore

Before you start System Restore, save any open files and close all programs. System Restore will restart your PC.

• Open System Restore by clicking the Start button. In the search box, type System Restore, and then, in the list of results, click System Restore. If you're prompted for an administrator password or confirmation, type the password or provide confirmation.
• Follow the steps in the wizard to choose a restore point and restore your computer.

After that the computer would restart and check if the computer is working fine.

NOTE: With system restore you will not lose any data from the computer