when you deploy any website on IIS basically each page has HTTP response headers and that shows your web site information like
1. Server – Specifies web server version.
2. X-Powered-By – Indicates that the website is "powered by ASP.NET."
3. X-AspNet-Version – Specifies the version of ASP.NET used.
Now, you can hide them using following ways
1. The Registry key,
2. URLScan tool
4. Using the httpRuntime element
see below link for details
Editor, DotNetSpider MVM
Microsoft MVP 2014 [ASP.NET/IIS]