If you have multiple Sandbox instances, you may take advantage of the Winter '10 Preview OR retain the existing Summer ‘09 functionality on each instance.

If you would like one or more of your Sandbox instances to participate in the Winter '10 Preview on September 18th, 2009, click here.

If you would like one or more of your Sandbox instances to retain existing Summer ‘09 functionality until October 10th, 2009, click here.

FAQs About Force.com Sandbox and the Winter'10 Release

Question: Question: I do not want one or more of my Sandbox instances to participate in the Winter '10 Preview. What should I do?
Answer: If you decide you would like one or more of your Sandbox instances to retain the existing Summer '09 functionality until October 10th, 2009, click here.

Question: I want my one or more of my Sandbox instances to participate in the Winter '10 Preview prior to the upgrade of my production instance. What should I do?
Answer: If you decide to take advantage of the Winter '10 Preview in one or more of your Sandbox instances click here.

Question: What happens to my Sandbox instance if I submit a refresh before 12:01 AM PDT September 10th, 2009?
Answer: Please note, if you submit a Sandbox refresh between 12:01 AM PDT September 10th, 2009 and the upgrade of your production instance, your Sandbox instance will retain the existing Summer ‘09 functionality until October 10th, 2009.