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About defragging hard drives

  1. May 25, 2009 #1
    I would like to know how to "defrag" a hard drive, and what the gains are to doing so. I am using windows vista home premium 64-bit with a single hard disk installed into my computer. Where do I go to defrag my drive? How long does this take? Are there any potential risks of causing data damage or hardware/software malfunction by defragging?
  2. jcsd
  3. May 25, 2009 #2


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    In my computer, right click on the drive, select properties->tools and defrag.
    Then select the drive again and click defrag, takes 10-30mins
    Depedning on how full your drive is and what you use it for, it can make a big difference.
  4. May 25, 2009 #3


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    Depending on your operating system and how much defragging you need, a first time can take hours. When I got XP I was told I no longer needed to do a regular defrag.

    If there is a problem yes, defragging can hose you up.

    Yep, Just looked it up, here you go. He's also correct about running a scandisk first. We also deleted temp files through DOS.

    Post 6

    http://www.computing.net/answers/windows-me/is-defrag-necessary/44453.html [Broken]
    Last edited by a moderator: May 4, 2017
  5. May 26, 2009 #4
    My two cents:)

    Prior to a defrag its good to run diskcleanup and chkdsk. Note that the Windows defragger needs atleast 15% free space to defrag. In Vista, the defragmenter is set to defrag on a specified schedule (I think 1pm on Wednesdays IIRC) and it lacks the fragmentation visuals as in the XP defragger. You can access the Disk defragger from Start>Accessories>SystemTools>Disk defragmenter. Another option is to go in for a completely automatic defragger like Diskeeper which once set in real time, defrags automatically even as you use the PC when its idle. (It also defrags in <15% free space)

    Defragging speeds up data access, so the HDD works more efficiently and contributes to overall system speed, preventing slowdowns.

    That normally depends on how fragmented the drive is, how much free space you have and what defrag program you run. Typically the more often you defrag, each time it shouldnt take more than afew minutes.

    I personally havent heard of or experienced any problems during or after a defrag.( I run DK in the automatic mode) However its a good precaution to ensure there is no power outage during the process. In anycase, its always good to have a backup of important files. Besides that there isnt anything to worry about.
  6. May 26, 2009 #5


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    I use 2 hard drives, each with multiple partitions and a 2 instances of the OS installed to peform a backup, compare, format, restore, compare sequence on partitions to backup, defrag them. Each instance of the OS can back up the partition of the other OS. The boot partition, usually "C:" can't be easily formatted and restored because of the partition and boot sectors, so I leave that alone, and only keep a minimal amount of stuff in it. I use other paritions for the OS and yet other partitions for applications and data to make restoring an OS partition faster (less data to restore).
  7. May 27, 2009 #6
    Disks are divided into physical entities called sectors. These sectors take only a limited amount of data, say 2048 bytes (it varies somewhat). The files you have are usually much larger than a 2048 bytes though, which means your file is spread out among multiple sectors. Now, if these sectors are not continuous (as in the first part of the file is on sector A, the next part on sector B, and so on), the disk will have to spend time seeking a new sector for each 2048 bytes its want to read.

    So, defragging is the process of reading files and rewriting them, making sure that they are stored continuously. This way, no time is spent seeking when you read a file, and access to the data on the disk is much faster.

    Modern OSes and file-systems do a pretty good job of building these continuous files on the fly, but over time the data will still become fragmented. So once in a while you want to run defrag.

    It is not dangerous at all. Data being moved is only copied at first, then read back, and when it is confirmed readable from the new location, the pointers are updated and the original deleted. You are just as likely to loose data when you move a file as you are when you defrag.

  8. May 27, 2009 #7


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    There is a free disk defragger from AusLogics which is much faster than that supplied by Windows. You can get it from CNET.
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