how to disable the asp.net button on page load Server side

Mention blow code will help you to make an asp.net button disable on server side page load event you can use it as per your requirement i.e. onclick event or where ever your want.

Code in .aspx page

Code aspx.cs File

protected void Page_Load(object sender, EventArgs e)
    {
    Button1.Enabled = false;
    }