If the drive you are converting is the drive with all your operating system files (usually C), then the file system change will not take place until you reboot the system. If your drive letter is C: You would type: convert c: /FS:NTFS In the command prompt window, type: convert drive_letter: /fs:ntfs Open Command Prompt by going to Start, All Programs, Accessories, and then click Command Prompt. To convert a volume to NTFS from the command prompt If this goes wrong it can potentially damage your operating system, and you may find re-installing windows is the only way back. Warning - before changing your file system, ensure you take a backup of your important documents. If your file system is not NTFS, you can change this by following the below steps. You will now see the C: Drive dialogue page like the one below, and you can see my system is using the NTFS File system. To find out what your computer is using, go to My Computer, then right click C Drive and go to Properties. NTFS is also more recoverable and better for storage purposes. NTFS is the more secure and newer file system. Your File system will either be FAT32 or NTFS. How to convert FAT32 NTFS File system in Windows X