为什么我的电脑speaker的音量很低?

I have a pair of regular speakers on my desktop. My desktop has two OS En and Ch. WinXP. Speakers works fine(loud) in En WinXP. But in Ch WinXP, I have to turn the volume to very high to hear it. All the settings are the same, system running smoothly and computer is maintained under good hand. Do you know what's wrong? Thanks!