Windows 11 mandates strict driver signing. Many older EasyCap drivers are not signed, which can lead to installation errors.
Getting an (USB 2.0 Video Capture Adapter) to work on Windows 11 driver easycap windows 11 upd
This error indicates the driver is not installed. Ensure the EasyCAP is plugged directly into a USB 2.0 port on the computer's motherboard, not a USB hub or the front panel of the case. Then, reattempt the manual driver installation steps above. Windows 11 mandates strict driver signing