Reckon is asking you which folder you want the backup file to be restored to.
That folder will depend on how you have your documents filed in your My Documents folder.
For example, do you have folders and sub-folders etc. and keep your Reckon file in a sub-folder named, "Our Finances" ? I am the voluntary treasurer of a charity, so I use two Reckon files. I keep one Reckon file named "Our Finances" in the "Our Money" sub-folder, and the other Reckon file named ""Name of Charity" in the "Charity" sub-folder.
Before you discard your old computer and its Reckon file, remember to print or copy to Excel a series of Reports of Account Balances, Cash Flows for various periods, including Cash Flows by Tag if you use Tags, etc. You can then compare the Reports produced by Reckon on your new computer with those produced on your old computer. If the Reports contain different data, you will need to explore things further.
I hope this helps