@ roro
Go to Start on your Windows 7 system then enter Windows Defender then you will see its current definitions and update level and you can set its Quick scan timing.
I have mine set for once per day at 7:00 AM and current is:
Client Version: 6.1.7600.16385
Engine Version: 1.1.6103.0
Antispyware definitions: 1.89.207.0