You must have the tax data file for the prior year copied to the hard drive of the new computer where you installed TurboTax for 2016. The tax data file has a file extension of .tax2015 and preferably should have been copied to Documents. The TurboTax program will search for any prior year tax data files when you first start a New Tax Return and will provide a list of data files found. You select which file you want to transfer to the 2016 return. If no data files found, you can browse to the location where the tax data file was copied.
See this TurboTax support FAQ - https://ttlc.intuit.com/questions/1901474-how-do-i-move-my-tax-data-file-to-another-computer
