This post  covered how to merge PDF documents. In a similar fashion, you can also merge text (.txt) files with Text File Joiner. With that software you can instantly join two, or more, text documents together.
To get started, just add the software to Windows from this Softpedia page . There click Download from Softpedia to save Text File Joiner to your desktop as a Zip file. You can open the program’s window below directly from the Zip without extracting it. This is also a portable app that can be added to a USB (Universal Serial Bus) stick.
Now press the Select File button, and choose a few txt documents to merge together. The selected files are then listed on the window as in the shot below. You can remove documents from the list by right-clicking them and selecting Remove Item. Click the Separate file contents with a space check box to add some spacing between the merged text in the document.
Now press the Save Combined button. That will open a Save as window where you enter a title for the file. Press the Save button, and then open the combined text document as in the shot below.
So now you can quickly merge txt text documents without any copy and pasting required. Text File Joiner works on all versions of the Windows OS.