From HP's tech suport
Solution
To properly extend the desktop to a monitor or TV use the following steps:
1. Start the notebook with the monitor or TV connected.
2. Type Ctrl + Alt + F12 to open the Intel Graphics Controller Properties.
3. On the Devices tab, select Extended Desktop then click Apply.
4. Click OK to confirm the desktop change.
5. Set Primary Device to Monitor (Secondary Device will automatically change to Notebook).
6. Click Apply.
7. Click OK to confirm the desktop change.
8. Click OK to close Intel Graphics Controller Properties.
Try setting the resolution to 640x480@60Hz