Please note that I DON'T need to disable CHKDSK at boot. What I need is to actually remove the Dirty Bit. I have an external drive that is formatted as FAT32 and I want to convert it to NTFS, but every time I run CONVERT I get a message saying that the disk has the Dirty Bit set and cannot be converted. CHKDSK /F does not solve the problem. I don't get any message asking me to run CHKDSK when I boot or connect the disk, which sort of proves that the disk is not actually dirty. (I always remove the disk using "Safely remove hardware").