sorry for making it so complicated
i should've just split the actual file by sets or something instead of letting you join them.. my bad
i'll try and explain step by step then
1/ double click on hjsplit.exe after you download it (i uploaded the one i use here: http://sharebee.com/cdbfe96d
2/ now you should get the following green screen. click join.
3/ then you get this purple screen, click input file
4/ now choose the folder where you downloaded the file to and click open
then it goes back to the purple screen, click start. you must have downloaded all the parts for it to work