how to download C language?

give any website for downloading C language.

There are many free C/C++ compilers available. Notable ones could be Microsoft's Visual Express C++, Dev-C, Borland C/C++ compilers. Cnet has a whole section for that purpose. Note that some of the compilers listed at the Cnet site are try and buy.

Here are some links:
http://www.microsoft.com/visualstudio/eng/products/visual-studio-express-products
http://download.cnet.com/1770-20_4-0.html?query=borland+c+compiler&searchtype=downloads