diskpart clean zeros LBA 0 to LBA 2047

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  1. Posts : 7,063
    Windows 7 Home Premium 32 bit
    Thread Starter
       #11

    Definitely. Clean command not only zeros sector 0 deleting the MBR code and partition table but
    also zeros all the sectors upto 2047.

    I do not know what sort of installation failures you are talking about and also I am not an installation specialist by any stretch of imagination. My own conviction is that if the HDD has been wiped clean to start with there should be no installation problem at all.

    What all I wish to convey is if one is recommending diskpart clean on a working HDD, it is always prudent to check before the 63 or 2048 factor. Safe if it is 2048 ,destructive if it is 63.
      My Computer

  2.    #12

    I'm sorry jumanji I am not getting you at all.

    Please explain exactly how these findings could affect wiping the hard drive with Diskpart Clean Command which is what we have been recommending for installation failures for years. There have been no complaints about it being unsafe, and it is intended to be destructive of MBR, partition table and by extension data.
      My Computer


  3. Posts : 25,847
    Windows 10 Pro. 64/ version 1709 Windows 7 Pro/64
       #13

    I need 4 brain cells because my 3 brain cells are not getting the job done on this subject.

    My understanding is the Diskpart Clean Command is designed to wipe the MBR and partitions and the Clean All Command was designed to not only wipe the MBR and partitions but also wipe the whole drive.
    I'm not understanding why one would care what little spot on a hard drive the MBR is located. It's either wiped or it isn't.

    If a recovery program is used to get data it either gets the data or it doesn't. Where the data is located on the drive doesn't matter.

    When you do a Clean Command only; you will be able to install Windows 7 which will make a new MBR and partition and install Windows 7. The rest of the garbage on the drive will be gone when it's wrote over buy new data installed. If you do a Clean Command All once again you just install Windows 7 and nothing has to be wrote over to remove it.

    What do I not understand? I'm sure trying to understand.
    Maybe I will never know.

    For sure I don't understand this. What is destroyed. Can't one just format to NTSF and get on with their lives.

    Safe if it is 2048 ,destructive if it is 63.
      My Computer


  4. Posts : 7,063
    Windows 7 Home Premium 32 bit
    Thread Starter
       #14

    gregrocker said:
    I'm sorry jumanji I am not getting you at all.

    Please explain exactly how these findings could affect wiping the hard drive with Diskpart Clean Command which is what we have been recommending for installation failures for years. There have been no complaints about it being unsafe, and it is intended to be destructive of MBR, partition table and by extension data.
    Sorry Greg, I got confused by the terminology you used and in the process confused you.:)

    A quick explanation:

    1. On a guestimate almost 95% of Windows 7 Systems, the start sector - the beginning of the first partition is LBA 2048.

    2. Rest 5% can have the start sector at LBA 63

    Note: When I formatted my external drive with Windows Disk Management, the start sector is LBA 2048.

    When I formatted the same drive with bootable PW, the start sector is LBA 63.

    The same applies to system drive. When installed from the Installation Disk maintaining the System
    Reserved partition, the System Reserved partition will start at LBA 2048.

    If I format the drive with PW before installing Windows to eliminate the System Reserved Partition,
    the first partition will start at LBA 63

    The point to note is there are systems with partitions starting at LBA 63.

    When you advocated diskpart clean for "Windows Installation Failures" it is quite possible that all systems you dealt with had the starting partition, (where the NTFS File system is written during formatting) at 2048 that constituting 95% of the population. Though it wrote zeros to all sectors 0 to 2047, the file system on 2048 is still in tact. Partition Wizard during scan will identify the starting partition by the NTFS file system present and successfully write the partition table on to sector 0. You will also Rebuild MBR to write the MBR code. All operations successful and the drive now is accessible as before. You can claim 100% success.:)

    Take my case. On my system preformatted before installing Windows 7 in 2009, the starting sector is on LBA 63.Now that I know that diskpart clean writes zeros to all sectors upto 2047 and will wipe the NTFS file system on it making it impossible for PW or any other utility to find the beginning of the first partition, I will not run it even if you advise me to do it to resolve any boot related problem..That would be inviting further trouble.

    In the case of lonewolfs he accidentally ran diskpart clean and the NTFS file system on Sector 63 has been wiped clean with zeros.(Sector 2048 did not show NTFS File system)

    In Shashank08989's case, based on his complaint that someone recommended diskpart clean and after that he lost the drive, I presume he also had the NTFS file system on Sector 63 and it is now wiped clean. You have recommended Partition Wizard and if it does not find the NTFS file system on Sector 2048 and rewrite the partition table, it is confirmed. Let us wait and see.

    I have explained things to the best of my ability.
      My Computer

  5.    #15

    What might symptoms be if wiping with Clean command to clear the partition table and MBR to enable Win7 install on a LBA 63 drive caused "further trouble?"
      My Computer


  6. Posts : 7,063
    Windows 7 Home Premium 32 bit
    Thread Starter
       #16

    Sorry, I do not understand your question.
      My Computer

  7.    #17

    You said you wouldn't use Diskpart Clean command to wipe the drive of an LBA 63 drive even if it is a known solution to install failure. What kind of problems do you think it could cause exactly since the MBR and partition table is formatted during install afterwards.

    I don't know what we would even look for and no damage has previously been reported. It just works.
      My Computer


  8. Posts : 562
    Windows 7 Ultimate x64
       #18

    To my understanding, Greg or any other helper in the forum never advised to clean the partitions on a disk with data on it. If there is no valuable data to be saved on the disk, there is no further complications in using DISKPART CLEAN command.
      My Computer


  9. Posts : 7,063
    Windows 7 Home Premium 32 bit
    Thread Starter
       #19

    No it is not a known solution in case where the start sector is 63. Greg, you have to define what is the install failure you are talking about.
      My Computer


  10. Posts : 12,012
    Windows 7 Home Premium SP1, 64-bit
       #20

    If I'm reading this correctly, the difference is that if you formatted with PW or any tool that uses LBA 63 rather than 2048, and later run Diskpart Clean, you will not then later be able to recover the partition.

    If you use Windows Disk Management to format, you would be able to recover the partition after a Diskpart Clean because WDM uses LBA 2048, not 63.

    So--if possible, use WDM or some other tool that will format using LBA 2048--to increase the likelihood that you would later be able to recover a partition.

    Do I have that right?

    What formatting tools are known to use 2048?
      My Computer


 
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