Most USB drives have a MBR partition style and will work fine on our CTOUCH screens. In case your USB drive has GPT (GUID Partition Table) please follow the steps below to set it to MBR
WARNING back up all files from your USB-Drive before proceeding and instructions below are on own risk since selecting the wrong disk can erase all of your PC's data!
Open Disk Management on your Windows PC
Check if your USB-Drive is GPT by right clicking the desired disk (6 in our case) and choose properties
Here you you can find the partition style from the Volumes tab
Since our USB drive has a GPT partition style as shown in the picture above you can close Disk Management and proceed to the next step to convert it to MBR.
Use Windows search to find Command Prompt and right click on the result to run it as administrator.
The command prompt will pop up:
Now type diskpart and press enter
Type list disk and press enter to see all available disks (only drives marked with * are GPT)
Type select disk followed by the correct number and press enter to select it. In our example disk 6
Only if you are 100% sure the correct disk is selected type clean and press enter
Now type convert mbr and press enter to go from GPT to MBR
Now you are set and you can close the Command Prompt