When your USB flash drive becomes RAW, you cannot use Windows’ built-in repair tool CHKDSK to fix the errors. This is because a RAW partition means its file system metadata is not recognized by Windows or is missing a file system. CHKDSK is designed to repair drives with the correct file system (such as NTFS, exFAT, FAT32). In other words, if a problematic drive does not have a recognizable file system, CHKDSK won’t run. In this case, you can use a specialized third-party tool to repair the RAW partition. After repair, the partition will become accessible and usable, eliminating the need to reformat the USB drive.
If the USB drive cannot be repaired, you can use the DiskPart command line to erase the device, create a new partition on it, and then format it to your desired format. [ Related how-to guide - What to Do When You Fail to Format External Hard Drive in Raw? ]