After I upgraded to 24H2 on one of my desktop computers I had the same issue with the realtek driver, and the sound on my external speakers was erratic. I tried everything I could think of and was unable to fix the error. I ended up purchasing this inexpensive external sound "card" and it works perfectly (though device manager still shows the same realtek driver error). If your sound is effected, you might want to try this: Amazon.com
Forgot to report what the problem is. Hope this helps someone else. The input device needs to be on Microsoft Array. Not sure why Stereo mix does not work. Wish it did to save all that headache and frustration.
The Stereo Mix is disabled by default and you have to enable it if you want to use it. Some sound cards display no output if you have not connected speakers or earphones. Similarly they display no input of you have not connected a microphone. This is supposed to not confuse novices with inputs or outputs that don't work, but I find it more confusing.
Samsung SSD 850 EVO 250GB SATA Device (250 GB, SATA-III)
Internet Speed
VDSL 50 Mbps
Browser
MICROSOFT EDGE
Antivirus
WINDOWS DEFENDER
Other Info
Legacy MBR installation, no TPM, no Secure Boot, no WDDM 2.0 graphics drivers, no SSE4.2, cannot get more unsupported ;) This is only my test laptop. I had installed Windows 11 here before upgrading my main PC. For my main PC I use everyday see my 2nd system specs.
Samsung 990 Pro 1TB NVMe (Win 11 25H2)
SK hynix P41 500GB NVMe 25H2 DEV/Games
SK hynix P41 2TB NVMe (x3)
Crucial P3 Plus 4TB
PSU
Corsair RM850x Shift
Case
Antec Dark Phantom DP502 FLUX
Cooling
Corsair Nautilus 360 RS AIO
Keyboard
Logitech MK 320
Mouse
Razer Basilisk V3
Internet Speed
350Mbs
Browser
Firefox
Antivirus
Winows Security
Other Info
MR 8.1 Home
System 3 Specs
Win 11 Pro 25H2 26200.8655
ASUS PRIME Z370-P II BIOS 3004 7/12/21
Intel Core i7-8700 CPU @ 3.20GHz
32GB DDR4 RAM (4x8)
iGPU Intel UHD Graphics 630
Operating System
Win 11 Pro 25H2 26200.8655
Computer type
PC/Desktop
Manufacturer/Model
Self Built
CPU
Intel Core i7-11700F
Motherboard
Asus TUF Gaming Z590 Plus WiFi (BIOS 2803)
Memory
64 GB DDR4
Graphics card(s)
MSI GeForce RTX 3060 Ventus 2X 12GB
Sound Card
SoundBlaster Audigy Fx V2
Monitor(s) Displays
Samsung F27T350
Screen Resolution
1920x1080
Hard Drives
Samsung 980 Pro 1TB
Samsung 970 EVO Plus 2TB
Samsung 870 EVO 500GB SSD