Multi Boot rin Flash drive ko using Ventoy pero hindi kopa na experienced yan Sir.
Try this method po
type CMD
1. diskpart
2. list disk--> usually 0 ay HDD at 1 ang Flash Drive
3. select disk --> disk 1
4. attributes disk set readonly --->set write protected = prevent ng lagay ng ibang files sa Flash Drive
5. attributes disk clear readonly --->remove write protected = back to normal ang Flash Drive
After mo gawin pero same scenario? try hard format sa flash drive
type CMD
1. diskpart
2. list disk
3. select disk
4. clean
5. create partition primary
6. select partition 1
7. active
8. format fs=ntfs or fat32 quick
9. assign letter= x
sana makatulong