I got a file from a friend that was split up (i assume by hj split). I used HJ split to join the files back together, but i have no idea what to do with the joined file, it's not a .bin, .cue, .iso, or a RAR, WinZip file either, when i look at properties to see what kind of file it is, i just says Filetype: File.
How large is the file? Also you can try the freeware Hex Editor XVI32 to read the beginning of the file and see what the header is.