ConCat/Split is a Windows Explorer context menu extension that provides two complementary facilities:1.

A split facility that lets you easily convert a single large file into several smaller ones.

You can copy these smaller files onto floppy disks, or send them through email facilities that will not cope with large files.2.

A file concatenation facility that performs the same operation as the command line "copy /b SrcFile1+SrcFile2 [+SrcFileN] DestnFile" operation.

With ConCat, you can append any number of files and store the result as a new file, or overwrite one of the original files.