Hi Alex,

Use the Delete Closed Jobs function. You will be given an option to copy to Archive. From the Help file about this:

You can delete closed Jobs from the database using this function. This will permanently remove the Job information from your JobCost data unless you have Retain archived jobs selected on the Company Profile's Options tab. If you choose to archive jobs, you will be able to view the Jobs that you have deleted from the list of Current Jobs. The Inquiries | Archived Jobs function will list these jobs and all of their details.

Any Jobs with the Keep as Template turned on will not be deleted by this function.