windows 7 - Access denied for external drives (FAT32) on Windows7 , Diskpart, takeown, nothing works

I have been trying (without any success) to access 2 external harddrives and a USB key on Windows 7, the 3 with FAT32 format. (for the fun I also formatted one in ExFat to try, didn't work)

The access is denied each time (the 3 devices work perfectly on Mac) ;
I tried :

• To change the permission on the disk


• To run takeown (on cmd and powershell)


• To run it as an hidden administrator


• To format it, clean it, change the attributes with DiskPart


• To format it through Disk Management (formatted it, still didn't get the access)


• To change the security key to 0 to get the permission

Each time, I get "Access denied".

Little challenge, I am currently recovering 2To of data from another harddrive with TestDisk, so I cannot restart the computer.

Any idea ?