I wanted to share this with you guys...
I bought a Nano 4th gen China clone on e-bay. It was supposed to have 16gb and after finding this forum and reading a little I knew I did not have 16gb and that the memory was hacked. After following the "How To: Removing Memory Hack" post my MP4 player was showing a disk error problem.
When I use the MP3 Disk Tool it shows 16362 mb of disk capacity in the Partition and Encryption tab. I deducted 2gb to that and I moved the Partition Slider to the Right until it was at 14314. Then I clicked on Start to begin the format and partition process. When it finished I disconnected it and turned it off for a minute and when I turned it on again I ended up with a working 2gb MP4 player
I also tried 4gb by deducting 4096 to 16362 and then using CompuApps SwissKnife V3 (it's free) to format the MP4 back to FAT. I then had a working 4gb MP4 player but after putting more than 2gb into it and trying to erase it gave me problems so the MP4 player has only 2gb. I redid the MP4 for 2gb and it's working great. I filled it up and deleted everything and it was OK. Then finally loaded my music again.
I don't have 16gb but at least it's working good now
I hope that this helps somebody else.
Have a good day! and enjoy your MP4 player... Thanks for this great forum!!