Courses and playback · Windows

Courses and playback · Windows

Course is slow to load or narration does not play on a Windows PC

If a course takes a long time to start, shows a blank screen, or skips its narration on your Windows computer, a Windows sound setting called audio enhancements may be the cause. This article explains how to check, and how to fix it in a few minutes.

Is this a problem you have?

You are likely experiencing this issue if most of the following are true:

  • The course shows a blank or white screen for 10 to 30 seconds before the first slide appears.
  • Narration starts late, is cut off, or does not play at all, even though the slide moves on.
  • Animations or slide timings feel stuck, as if the course is waiting for something.
  • It happens in every browser you try (Edge, Chrome, Firefox), including private or incognito windows.
  • The same course works normally on your phone or tablet, or on a colleague's computer, on the same network.

Figure 1. The tell‑tale pattern: the problem follows one Windows computer, not the course, browser or network.


2. Why it happens
Audio enhancements are extra sound effects, such as bass boost, virtual surround or volume levelling, that your computer's sound driver applies to everything you hear. They are usually installed by the computer manufacturer or by software such as Realtek, Dolby, Waves or Nahimic.

Every time a web page plays a sound, Windows has to start these effects up. On some computers, often after a Windows or driver update, this start‑up takes several seconds or stalls completely. Most apps open one sound channel and keep it, so you may never notice. Online courses open many short sound clips as you work through them, so the delay builds up into a long blank screen and missing narration.

Turning the enhancements off removes the delay. It does not affect the course content, and for most people the sound will be unchanged.

3. Fix it on Windows 11

  1. Close the course and your browser.
  2. Press Windows + I to open Settings, then select System › Sound.
  3. Under Output, select the speakers or headphones you normally use (the one with the dot next to it). This opens its Properties page.


Figure 2. Settings › System › Sound. Select the output device that is in use (illustration; names will vary on your computer).

4. Scroll down to Audio enhancements (on some versions this is a switch called Enhance audio).
5. Change it to Off, or turn the switch off.


Figure 3. Set Audio enhancements to Off (illustration).

  1. If you switch between devices, for example laptop speakers and a headset, repeat steps 3 to 5 for each one.
  2. Reopen your browser and start the course again.

4. Fix it on Windows 10 (or the classic Sound panel)

These steps work on both Windows 10 and Windows 11.

  1. Close the course and your browser.
  2. Press Windows + R, type mmsys.cpl and press Enter. The Sound window opens.
  3. On the Playback tab, select the device marked with a green tick, then select Properties.
  4. Open the Enhancements tab and tick Disable all enhancements. On some computers this is on the Advanced tab, where you untick Enable audio enhancements instead.
  5. Select Apply, then OK.


Figure 4. Classic Sound panel: Enhancements tab with Disable all enhancements ticked (illustration; options listed vary by computer).


5. After the fix


You can leave enhancements off. If you want them back for music or films, first check your computer manufacturer's website for an updated audio driver, install it, then turn enhancements on again and retest a course. If the delay comes back, turn them off again.

6. Still having problems?

Try these in order, reopening the course after each one:

  • Choose a different output device. In Sound settings, switch to another device, for example your laptop speakers instead of a monitor or USB headset.
  • Disconnect Bluetooth headphones and test with wired headphones or built‑in speakers.
  • Turn off exclusive mode. In the classic Sound panel (mmsys.cpl), open your device's Properties, then the Advanced tab, untick both Exclusive Mode options and select Apply.
  • Update your audio driver from your computer manufacturer's support website, then restart your computer.

If none of these help, contact our support team and tell us:

  • the course name and what you see (blank screen, missing narration or both)
  • your computer make and model, and your Windows version
  • the browsers you have tried
  • whether the course works on another device