[Roy Dennis]

Is this a new Windows 10 laptop or an upgraded one ?

Did you install the latest video drivers because of this problem ?

When you say you installed the “latest recommended video codecs” did you install the K-lite Mega pac ?

When you start a video playing do you see an icon on the taskbar for something like Lav or FDshow it might be hidden under the up arrow which shows the hidden apps ?

If so what icons appear ?

What you can try:
Left click on the windows icon bottom left of taskbar then all apps and scroll down to K-Lite codec pac, expand that and select codec tweak tool. At the top of the dialog you should see “Fixes” open that and select the first four tick boxes, then apply and close.
Try your videos again see if this fixes the problem.
If still no luck re open the tweak tool this time select “Prefered decoders” under that press “Reset” you should see another box asking “Click Yes for windows default. Click No to reset to our recommended settings” select NO.

See how you get on with that.

If problem persists try adding a screen shot of your preferred codecs dialog.