Welcome Kitty Holt,
Thanks for reaching out to Microsoft Q&A Forum. I understand that the Project feature on your laptop stays on PC screen only and does not switch to Extend.
To help narrow this down, could you please confirm:
- When you choose Duplicate or Second screen only, does the external display show anything, or do those options also fail to apply?
- Is the external display a monitor or a projector, and what is your laptop's brand and model?
Please make sure you already tried the Q&A Assist steps. In addition, please try the following:
1, Set Extend from Display settings instead of the Project panel
- Open Settings, select System, then select Display.
- Expand Multiple displays and open the drop-down menu next to the display options.
- Select Extend these displays, then select Keep changes when asked.
2, Check which display adapter Windows is using
- Right-click Start and select Device Manager.
- Expand Display adapters.
- If you see Microsoft Basic Display Adapter, Windows is not using the full graphics driver. Download and install the graphics driver for your exact laptop model from the laptop manufacturer's support website.
3, Install pending optional driver updates
- Open Settings and select Windows Update.
- Select Advanced options, then Optional updates.
- Expand Driver updates, select any display, graphics or chipset updates, then select Download & install.
- Restart the laptop after the installation.
4, Set the display mode in the graphics control app
- Open the graphics app installed on your laptop, such as Intel Graphics Command Center, NVIDIA Control Panel or AMD Software: Adrenalin Edition.
- Go to the Display or Multiple displays section and set the mode to Extended desktop.
- Apply the change and check whether Windows keeps the setting.
Looking forward to your update.