c# - Sharepoint 2010 - How can I define PROGRAMMATICALLY whether Office Web Apps installed on server?

Question

I am using C# programming language and want to define whether Office Web Apps installed on server in order to hide/show <SharePoint:MenuItemTemplate Text="Open in browser" />

My variant is as follows

bool b = File.Exists(@"C:\\Program Files\\Common Files\\Microsoft Shared\\Web Server Extensions\\14\TEMPLATE\\LAYOUTS\\WordViewer.aspx");

but I need something else... what is the correct method?