使用wincc6.2打开已有的工程需要注意以下的一个问题（摘自SIMATIC HMI
WinCC V6.2 SP2 Migration）

Entering the User Archives Option in the Startup List of WinCC Computer Properties

Starting with WinCC V6.0 SP2, the User Archives option must be entered in the startup list in WinCC computer properties instead of the "Additional Tasks/Applications" field.
In order to accept these changes in your existing projects, open the User Archives editor save your data.
Alternatively, you may update the startup list in WinCC Explorer in the "Computer Properties"（不是windows的计算机属性）
dialog using the "Startup" tab:
1. In the field "Additional Tasks/Applications", delete the entry "CCUsrAcv.exe".
在“附加任务/应用程序”选项里删除"CCUsrAcv.exe".
2. Activate the entry "User Archives" in the "Start Sequence of WinCC Runtime" field.
在“wincc运行时的启动顺序”选项里选择“用户归档”。


如果按照以上的方法还是不能激活，可以试着先去除掉变量记录和用户归档的功能再试试。