WD Elements SE Portable - Problem to format and files disappearing

Windows XP sp2
I recently get a TB WD Elements SE Portable -model number WDBABV0010BBK
I came formatted but I decided to reformate it. As I only had the box and no software coming with it I used HDDwipe.
Since then I cannot use any of the WD Tools to format it. It is not recognized by WD Quick Formatter for Window. But  Finally using EASEus I could make one 2TB big partition + MBR + and format it FAT32 with 32b clusters. It seems OK and I spent about one hour copying files on it … strangely some PDF files were copied but couldn’t be opened and more strangely many copied files and subfolders simply disappeared after a while. e.g I copied a big folder MYPIC and then when I open it  there nothing in. If i check MYPIC properties it says 0 files 0 folders BUT If  I check the whole disk space it counts for ever\ything that should be in MYPIC. So it seems the datas are not lost.   Anyone had the same problem ?
Should I consider : larger cluster ? GPT ? NTFS ? partitioning ?
Any Idea ?

Mate,

Reformat your drive in NTFS and repartition the unit.

With NTFS the computer simply has no access to the disk although you see it.
Partitionning you only get the first primary partition visible and you need to get it under FAT32  to have an access

After trying every solution possible I opened the box … I guess 4TB cannot be on such a small chip - Am I wrong ? - that can simulate 36 h of low level formating, allow a few files to be copied and so on … Ok it was cheap on Taobao and there are lots of them but …