If you run the Altera SDK for OpenCL version 15.1 on Windows 8.1 and you install an unsigned driver, you might encounter the following error messages:
difx_install_preinstall_inf: err e000024b, last event 0, last error 0.
difx_install_preinstall_inf: err e000022f, last event 0, last error 0.
Prior to installing an unsigned driver, disable driver signature enforcement by performing the following steps:
- On the Windows login screen or under the Charms bar, open the power options menu.
- Hold the Shift key while you click Restart from the power options menu.
- After your computer reboots, select the Troubleshoot option.
- Select Advanced Options.
- Select Startup Settings.
- When prompted, click Restart to reboot your computer.
- When the Startup Settings menu appears, press the F7 key to choose the Disable driver signature enforcement option.
After your computer restarts, you can install unsigned drivers.