Where is GACUTIL?

Thank you for the answer. But the fact is that it isn't. After searching I have found that something is wrong with the installation of Visual Studio so I'm uninstalling now and in one hour I will know if is there where you say
Thanks

I'm a really beginner but I'm going to tell you my expirence with this. Because yesterday I was asking my self (and to a lot of people to ) the same: "where is the gacutil.exe?

This firs is that in a correct installation of Visual Studio this utility is in "C:\Program Files\Microsoft SDKs\Windows\v6.0A\Bin", you also can use it with the "Visual Studio Command Promnt" from "Visual Studio Tools". IF IS NOT THERE, be sure that your installation is not correct.

What I did?

1.- Uninstall Visual Studio with this tool (or follow the instruction): http://msdn.microsoft.com/en-us/vstudio/bb968856.aspx
2.- Uninstall .NET Framework (all version) with this tool: http://blogs.msdn.com/astebner/pages/8904493.aspx
3.- Read the Visual Studio Readme before installing againg. The are some notes like desactivate windows update during instalation that are very recommended.
4.- Install Visual Studio

Now I have the util!

If you want to try other solution maybe this is useful:

http://social.msdn.microsoft.com/Forums/en-US/windowssdk/thread/006edcd4-888d-4b95-8454-9651dc298390/

Thanks to DCMonkey and Maddus Mattus for they comments.