DELL 755 OPTIPLEX

Hi Timmy. I'm Greg, an installation specialist, 10 years Windows MVP, and Volunteer Moderator here to help you.

1. Windows 10 already has DirectX 12 which is updated only by Windows Updates. So check for WIndows Updates at Settings > Update & Security > Windows Update > Check for Updates and expedite their install to make sure you have them all.
2. Update the Display driver from the PC or Display adapter maker's Support Downloads web page for your exact model number, HP Serial Number or Dell Service Tag - from the sticker on the PC.

While there check also for newer chipset, BIOS/UEFI firmware (very important), network, sound, USB3 and other drivers, comparing to the ones presently installed in Device Manager reached by right clicking the Start Menu.

If this doesn't give you the latest or ideal driver for what you need, compare it to the driver offered by the Intel driver update Utility here: http://www.intel.com/content/www/us/en/support/...

or the Nvidia Update utility here: http://www.nvidia.com/Download/Scan.aspx?lang=e...

or the AMD autodect utility here: http://support.amd.com/us/gpudownload/windows/P...

For Display issues one fix that is working is to Roll back or Uninstall the Driver on the Display Device > Driver tab, restart PC to reinstall driver.

You can also try older drivers in Device Manager > Display device > Driver tab > Update Driver > Browse > Let Me Pick.

Then you will know you've tried everything in addition to Windows Update drivers.

Adjust the screen resolution until it fits and looks best at Settings > System > Display.

If after that you still cannot install Google Earth then your display adapter doesn't support it.

I hope this helps.