Steps:
1. Pick a new jpg picture and rename it to A.jpg
2. Make a new .rar or .zip folder on your desktop. example A.rar
3. Add the files you want to hide into the .zip or .rar. example add katzy.txt to A.rar
4. Click start menu, run, cmd.
5. In Command Prompt type cd "desktop" with the quotation marks.
6. Now type in copy /b A.jpg + A.rar B.jpg
( If you use .zip then: copy /b A.jpg + A.zip B.jpg)
7. Now there should be the outputed file name  B.jpg. DONE
(if you wanna cek just rename B.jpg to B.rar)
Now you're done!
A quick info-fact:
With this technique of hiding files in a jpg you can send this to anyone and they just have to rename the file extension to .zip or .rar.
With this technique the Al-Qaeda operatives were able to send info to others secretively.

this is example:


save it, right click,  rename to b.rar and open with winrar
or
download example here
http://katzy.do.am/Download/b.jpg

Good luck it contain katzy.txt inside pic