Make sure that if there is no problem with the sound card and sound card driver (there is only no sound when turning on and off, no sound when playing flash, that is, no sound when playing web videos), you only need to import netvol.reg. The specific steps are: from /regs_edits /netvol.reg Download the attachment netvol.rar, unzip and release netvol.reg, double-click, the system will ask whether to import into the registry, click OK and you are done. No need to even reboot.

The reasons may be:

It is usually caused by using some optimization software or installing or uninstalling various decoders. To solve this problem, you can click "Start" menu → "Run", enter "regedit" and press Enter to open the Registry Editor. In the left pane, click "HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Drivers32" ", and then check whether there is a "wavemapper" value in the right pane. If not, right-click the blank space in the right pane to create a new string value named "wavemapper", then double-click the value to set its "numeric data" to "msacm32.drv" and restart the computer. Can solve the problem.

Tip: If there is no sound after setting up according to the above method, please check whether there is a volume icon in the system tray. If not, open the "Sounds and Audio Device Properties" and select "Put the volume icon into the taskbar" so that there will be sound.