Setting an Event to Null

I have a code like this:

public class SomeClass
{
    int _processProgress;
    public int ProcessProgress 
    { 
        get { return _processProgress; } 
        set 
        { 
            _processProgress = value; 
            if (ProcessProgressChanged != null) 
                ProcessProgressChanged(value);
        } 
    }

    public delegate void ProcessProgressChangedEventHandler(int progressPercentage);
    public event ProcessProgressChangedEventHandler ProcessProgressChanged;

    public void ClearProcessProgressChangedEvent()
    {
        this.ProcessProgressChanged = null;
    }
}

Will it unsubscribe all method in the ProcessProgressChanged event when I call the ClearProcessProgressChangedEvent() method?

My code is in C#, framework 4, build in VS2010 Pro, project is in Winforms.

Please help. Thanks in advance.