Go here and select your model:
http/esupport.sony.com/US/p/model-find.pl?mdl=Vaio PCG-61611L &PRODTYPE=9,26,2,1,77,72,24,5,54
Look for the user manual and find the section on how to do a system recovery. It may be something like this "How can I restore my computer system to its factory default settings?
There are two ways to recover your computer system: from Recovery Media and from the recovery area. For detailed
information, refer to a user guide under Use my VAIO in Help and Support (page 6) or enter VAIO Care, VAIO Care
Rescue, or VAIO Recovery Center in the search box in Help and Support (page 6)."