How to delete IIS custom headers like X-Powered-By: ASP.NET from response?

You can add this to your Web.Config:

<system.webServer>
    <httpProtocol>
        <customHeaders>
            <remove name="X-Powered-By" />
        </customHeaders>
    </httpProtocol>
</system.webServer>

Update: if you’re using the MVC framework I would also recommend removing the X-AspNetMvc-Version and X-AspNet-Version headers as well. This is accomplished by setting MvcHandler.DisableMvcResponseHeader = true in your Global.asax file and <system.web><httpRuntime enableVersionHeader="false" /></system.web> in your Web.config respectively.