I see I made a typo in my previous post, referring to your D:\ drive as F:\, apologies for that.
Normally the iTunes library will be at C:\Users\<Username>\Music\iTunes. Assuming you copied this folder to D:\ so it has become D:\iTunes then there is no need to rename anything. You can hold down shift as you launch iTunes and keep it held until you are prompted to choose or create a library, click Choose Library... then browse to and open the library file D:\iTunes\iTunes Library.itl. The .itl file extension is probably hidden. The .itl file is the database that knows what has been added to the library, where it is, and records things like date added, ratings, play counts, playlist membership, etc. that are not recorded in individual track tag records.
The normal layout of an iTunes library is an iTunes folder that holds the .itl file, some supporting files, and an iTunes Media folder that has all media content added to the library. When it is in this layout it is easy to move the entire iTunes folder as a unit to some new location and select the library as described. Things would become more complicated if, for example, you had copied only your media into a new D:\iTunes folder, leaving out the .itl file, or you have copied the data somehow without retaining the layout of the folders.
tt2