In win7:
Just delete all files in the C:\Users\admin\AppData\Roaming\Subversion\auth\svn.simple folder
Among them, AppData is a hidden folder, and it must be displayed before proceeding to the next step!
Show hidden files:
http://jingyan.baidu.com/article/af9f5a2dc1f91243150a4553.html
1.
2. Next, in the "Folder Options" dialog box that opens, click "View" and switch to the "View" tab:
3. Then in the "Advanced Settings" area below, uncheck the check box in front of "Hide protected operating system files"; then select the "Show hidden files, folders and drives" radio option below, and
finally click " OK" button to save the settings;