I have tried every voodoo wizardry imaginable to crack these cards. Diskpart, Regedit, and 3rd party softwares. Was successful in cracking through the 'read only' lock only to be left with 1mb of storage. 1mb is for any system that isn't Android. These cards are excellent if you install them in a phone, they WILL NOT FUNCTION FOR WINDOWS OR MAC. If you put them in a camera and USB to your PC, this only partially works but mostly not at all. Through a USB to phone they work perfectly. Recommended for use with phone only.