Error message: Event Log is Full (trying to do a walkthrough)

Hi:
I'm trying to do the "Walkthrough: " Basic data access in web pages".
 I get to the point where you are click the DB connection (new SqlDataSource1) then, under Configure Data Source, click on the button, "New Connection". (There is nothing in the drop down text box to its left) When I click new connection, I get the error box: Event log is full.
I have no idea why its full as this is first project I've tried.
 Can anyone help please??

Rae

 
 
 
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