Only by performing a Repair installation of Windows. Media Center is a core component of the operating system, rather than a removable one.
Are you sure that Media Center is truly gone, and that it's not that the shortcuts were simply deleted?
Try this:
Navigate to C:\Windows\ehome (that's the Media Center root folder - just type that into any Explorer window) - is the folder still there? If it is, is there a file called ehshell.exe ? If there, is, does double-clicking it launch Media Center? If it works, then MC is still there and is registered. If it doesn't work, do you get an error message?
