Normally, Equalizer APO provides freedom to change and improves your computer sounds. To fix this issue, you should fix Realtek sound drivers and read the below blog. For more details, you should visit to www.office.com/setup.

Method To Fix If Equalizer APO and Realtek Sound Drivers Problem:
- Update Drivers:
To fix this issue, you should use tool to automatically update and replace your outdated and buggy sound drivers. It also scans your computer system to find driver issues and after this, it downloads and installs the right versions. It will provide up-to-date versions which improve the performance of your device. The user can also use DriverFix tool in order to scan the drivers’ issues and just updates them in minutes.
2. Install SFX/EFX:
For installing, you should press Windows key and then look for the Configurator. After this, you need to choose the Equalizer APO Configurator. Then in Playback devices tab, you should mark all the devices which you’ll use with the equalizer. Here, you need to mark the checkboxes which are next to Pre-mix and Post-mix. At this point, you should select Troubleshooting options checkbox. Then from the dropdown menu, you should choose Install as SFX/EFX. At last, you need to Save your settings and then just exit the Configurator.
3. Disable Hardware Acceleration for Audio Devices:
You need to open Control Panel and then choose Hardware and Sound. After this, you should tap on Sounds. Here, you should tap on the Playback tab. Then, you should right-tap on the audio device and then choose Properties. At this point, you should visit to the Advanced tab. Now, you should uncheck the box of All hardware acceleration of audio with this device. Lastly, Save your settings and then tap on OK button.
4. Turn on all Enhancements:
First of all, you should open the Control Panel and then choose Hardware and Sound. Now, you should tap on Sounds option. Then, you have to switch to the Playback tab. After this, you should right-tap on the sound device and then choose Properties. At this point, visit to the Enhancements tab. Lastly, you should unmark the checkbox Disable all enhancements and then tap on OK button.
5. Use Windows Registry:
For this, open the Registry Editor with admin rights. Now, open the Start menu and then open the Configurator. After this, tap on the Playback devices tab and then select the device which you want to use with equalizer. Then, tap on Copy Device command to clipboard button. At this point, you should open Notepad and then tap on CTRL + V altogether to paste the command. For security, you should back up your registry. Here, you should tap on Windows key and then look for regedit. Next, right-tap on Registry Editor and then choose Run as administrator.
For Identifying the correct value. First, in the Windows Registry, you should go to the below folder:
HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\MMDevices\Audio\Render
Then, you should tap on the arrow which is next to the last key in order to expand it. At this point, you should find a key name with the string.
To Modify Permissions for it:
The customer should first right-tap on the key and then chooses Permissions option. After this, tap on Advanced option. Now, you should tap on the Change link. Here, you should input Everyone in the field and then tap on Find name and then tap on OK button. Next in Advanced Security Settings, you should mark the checkbox of Replace owner on subcontainers and objects. At this point, you should tap on Add button and then hit on Select a principal link. Then, you should input Everyone and then complete the name and then tap on OK button. From the Basic permissions area, you should choose Full control. Here, you should apply the changes and then close the dialog box. After this, you should Return to the Registry Editor and then right-tap on the key. Next, you should delete the key and then reboot the machine. At last, you should re-install APO with the Configurator.
For more information, the customer should hit on www.office.com/setup.