原因是用户的profile文件破坏，需要先将个人文件夹中的数据备份后，删除用户profile由系统重建即可。参考：http://support.microsoft.com/kb/947215/en-us

1. Delete the profile by using the Computer Properties dialog box. To do this, follow these steps:
2. Click Start, right-click   Computer, and then click Properties.  
3. Click Change settings.
   
   
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4. In the System Properties dialog box, click the Advanced tab.
   
   
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5. In the User Profiles area, click   Settings.
6. In the User Profiles dialog box, select the profile that you want to delete, click   Delete, and then click OK.
7. Click Start, type regedit in the Search box, and then press ENTER.
8. Locate and then click the following registry subkey:
   HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList
9. Right-click the SID that you want to remove, and then click Delete.

Log on to the computer and create a new profile.