This means that mysql cannot find the table it uses to store usernames. It may be corrupt or deleted.
To resolve it;
Goto mysql data folder e.g. D:\wamp\bin\mysql\mysql5.0.51a\data\mysql and make sure you have these three files user.frm user.MYI AND user.MYD
if they are missing you can download them from here and replace all 3 files.
Restart wamp and your icon should go white :)
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