求助，请教一个问题，关于eclipse安装pydev插件问题

[jiashadidai]

Your original request has been modified.
"PyDev for Eclipse" will be ignored because it is already installed.
Cannot complete the install because one or more required items could not be found.
我明明已经安装了pydev插件！可是，在配置pydev解释器时，在Window > Preferences中找不到pydev这一项！！
怎么办 ？？谢谢帮忙！！

[xgdgsc]

清理一下eclipse的配置。