CustomValidator does not fire

Recently, I needed to ensure that a user fill in one of two TextBox controls on a form I was designing. I couldn't use two RequiredFieldValidator controls as that would mandate that both fields be completed. I therefore created a CustomValidator control and added it to the page. It did not work. There was a flaw in my thinking. The control did not ever fire when needed (ie. when both fields are blank), because the control does not, by default, validate blank fields. Thankfully, there is a way to change this. You can set the ValidateEmptyText to true:

<asp:CustomValidator ID="myValidator" runat="server" ErrorMessage="Error message" OnServerValidate="myValidator_ServerValidate ValidateEmptyText="true"></asp:CustomValidator>

Windows does not shut down

Slightly off-topic, but if your computer does not respond to an ordinary shutdown command, you can force a shutdown. To do this, select Start, Shutdown in the usual way and, as you click OK, hold down the control key. Use with care as this might terminate processes uncleanly. Always back up your data.