I have an external USB hard drive with a defect in master boot record. When I plug in the USB HD, my computer detects it and assigns a letter (D to it. However, I cannot format it, as I got an error message related to I/O error. I know it is a master boot record error, because when I used another software (couldn't remember the name), it says that the disk has a master boot record error. Question: 1) Is there a free software that can repair the external usb hard drive? The software must be able to run on Windows 7 64 bit OS.
Search for free edition MiniTool Partition Wizard. Select the drive and select the Rebuild MBR feature. Click 'Apply' to start the operation.
Thank you very much for your advice. After downloading MiniTool Partition Wizard, as you can see below, I cannot choose anything. All it says is (Bad disk). Also, it can detect the drive. I am not sure how to continue from here?
If you have a Win 7 install disk or a repair disk, boot up with it. Don't install Windows, instead select 'repair computer' and get to the command prompt. Type: diskpart <enter> list volume <enter> If the disk is detected and you can equate one of the volumes listed to a listed letter, note the letter. Type: exit <enter> Type the letter followed by a colon, eg if the letter was F, type: f: <enter> At the prompt, type: bootrec /fixboot <enter> bootrec /fixmbr <enter> Reboot the PC and see what you get.
Try another free software partition assistant (standard edition) which is similar to partition wizard and the operation steps are also very like. http://www.disk-partition.com/help/rebuilt-mbr.html Maybe it works. Good luck!
Paranoid me thinks you have malware. What is in favor is one that rewrites your MBR and infects your firmware of both your computer and HD. If that is the case what you have is incurable. It is a firmware malware. What you can do is try to overwrite it with a blank MBR or better yet a backup you made. I doubt you will be able to do this because the firmware will not allow you to write to the disk. Did you connect to a different computer with that external? https://www.kaspersky.com/blog/equation-hdd-malware/7623/ After all these years it is still unstoppable and indestructible. If you think an unstoppable and incurable malware is rare I have a bridge you can buy cheaply. I will be interested to see what happens. I hope I am wrong but most everyone that has HD problems has your problems. I was infected about 6 months before this article was written. Obviously it wasn't very rare even then. The only way it can be detected is using partition software. If it is operating fine but you can't alter your MBR you ought to be suspicious.
JianWuDk, do as scorp says as could be the drive enclosure is causing the problem not the actual hard drive itself.
Yes, what @Mez said may be the cause since i have saw an article introduced several malware while WannaCry is popular. According to your description, yours maybe Fanny Worms. Just for security, have a check.
