Next time, make the question a bit more understandable...
Anyways, if you want the 'D-Disk' (down disk), if I remember it is located in Team Snagem's base. I think you can find when you go there the second time after recieving the e-mail, and battling Gonzap + confirming snag machine is not working. If not, just do the things that you are told to do by Nett and such by e-mail, and look for sparking items on the ground and such.
Note that the serebii walkthrough's information on where to find is is not very clear and possibly incorrect... (walkthrough says Team Snagem hideout has 'U-disk', item's location pages says otherwise...)
Hope I helped.