@Radtree since you are using Windows TurboTax Home & Business, the data from all the past years should already be on the machine. Look at the federal carry-over sheet. If you foreign taxes this current year and are filing a form 1116, TurboTax should automatically populate and use the carry-over credits available.
You can also go to forms mode and see the carry-over sheet and also the form 1116 worksheet.
Is there more I can do for you ?