Stop Asset Store dialog displaying at startup

How can I stop the Asset store dialog displaying at startup.
The dialog sometimes takes an inordinately long time to load and I get impatient.


Just closing it after it loads should fix it, because by default it doesn’t load with Unity.
If that doesn’t help, try to load some preset of layout, that should remove Asset Store window as well, until you open it again and integrate it in current layout.

Just for the record, for me Asset Store freezes Unity 4.6.1 completely.