經常聽見有人說用Windows 7玩網絡游戲的時候網絡延時比較高，也就是ping比平時xp的時候高一點，一直找不到原因，很苦惱。今天我們終于找到理由了，原來是Win7的一個服務在作怪，這個服務叫：Multimedia Class Scheduler。

這個服務的官方解釋是：

The Multimedia Class Scheduler service (MMCSS) enables multimedia applications to ensure that their time-sensitive processing receives prioritized access to CPU resources. This service enables multimedia applications to utilize as much of the CPU as possible without denying CPU resources to lower-priority applications.

MMCSS uses information stored in the registry to identify supported tasks and determine the relative priority of threads performing these tasks. Each thread that is performing work related to a particular task calls the AvSetMmMaxThreadCharacteristics or AvSetMmThreadCharacteristics function to inform MMCSS that it is working on that task.

For an example of a program that uses MMCSS, see Exclusive-Mode Streams

就是這個服務讓我的PING如此高，問題是找到了，那么我們如何解決呢？很簡單，禁用它就行了。

禁用方法：開始--運行-regedit，展開[HKEY_LOCAL_MacHINE/SYSTEM/CurrentControlSet /Services/Audiosrv]雙擊打開右側的DependOnService項目，把MMCSS刪除（千萬別刪到其他的），最后保存退出。

重啟電腦后設置才會生效，然后到服務里關閉并禁用Multimedia Class Scheduler，再進游戲看看有沒有提高呢。