# Is it REALLY Necessary to ScanDisk before Defrag, and why?



## Gary R (Aug 9, 2001)

I see recommendation's at times that ScanDisk should ALWAYS be ran before DeFrag, but no explanation as to _why_ it should be.

Ok, WHY is it necessary to ScanDisk first? I Standard scandisk/defrag weekly, but am curious as to why ScanDisk is used so much. 
Why wouldn't, say, Defragging weekly, or twice a month, and running ScanDisk once per month work?

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40 Gb. HD with 37.1 Gb. Free space. I don't think I've ever ran a thorough scan since I bought the computer in July 2001.

Windows 98SE (Ver. 4.10.2222A); No Upgrades since July 2001.
Internet Explorer 5.50; No Upgrades.


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## hewee (Oct 26, 2001)

Scandisk finds and fixes errors.
If you ever have any and do a defrag the defrag will stop and tell you to do a scan.
So just doing the scan first is the easy way to know all is well.


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## NiteHawk (Mar 9, 2003)

Is it necessary to run ScanDisk before running Defrag? NO
Is it preferred to run ScanDisk before running Defrag? YES

As Hewee pointed out, if you run Defrag and it encounters a disk error it will abort out and tell you to run ScanDisk.

Since 99% of the time you will have no disk errors (in normal operation) running ScanDisk becomes a waste of time.

Again, assuming normal operation and no errors, I would run Defrag once a month and perhaps ScanDisk once every 3 to 6 months. Unless you have reason to suspect you may have disk problems.

If you use 2 physical hard drives (say 2 40gig or 2 80gig (they don't even have to be the same size)) and then partition each in a reasonably logical manor you will find that you have to Defrag many of the subsequently partitioned drives less and less and some, not at all.

Assume for a moment 2 80gig HD's each with 5 to 6 partitions with the largest partition being 30gig. The total of 2 80gig HD's is 160gig, but is it faster to defrag several smaller partitions of 5 to 30gig, or one single partition of 160gig? As I said before, if you plan the layout right, there are 2 to 4 partitions that will NEVER have to be defragged and another 3 to 5 that will only need defrag once every 6 months or so. This of course will vary by how and what for each person uses their PC.

*EDIT:*

I have received several questions and PM's on the above. Let me restate that the above is based on running 2 physical Hard Drives with multiple partitions on each. With a single HD and single partition you will have to run both utilities more frequently.

The simplest way to put it is to separate the files that don't change from those that do.

No where is it cast in stone that files and folders like the swap file, Temporary Internet Files (TIF), Temp, Recent, Cookies, History, and Favorites and others *have to be* in the same folder or even on the same partition or HD as Windows. Since 90+% of the changes that take place (and hence fragment files) take place in these files and folders, doesn't it make sense to isolate these from the rest of your programs and files by putting them into another partition?

IF you have a second physical HD create the first partition as a small 500MB partition and place the swap file there. Create the second partition in the range of 500MB to 1 gig and place the folders for TIF, Temp, Recent, Cookies, History, and so on (depending on what you do and don't want to save) in that partition.

Now, instead of wasting time defragging all the garbage files, just delete them. Without these ever changing, ever growing files and folders in the Windows partition, it will have to be defragged less often. The same with partitions created for Programs, Data, Multimedia, and so on. It takes far less time to defrag a partition that to defrag a whole HD that has a single partition.

I hope that this has been helpful.


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## flavallee (May 12, 2002)

Gary:

I run Disk Defragmenter about once a week and Scandisk about once a month. Only when I run them both on the same day do I run Scandisk *first*. I run Disk Defragmenter about once a week because it gets fragmented enough during that time to require it.

By the way, I use the Windows ME version of Disk Defragmenter because it runs much faster than the Windows 98SE version does.


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## Cowboy622 (Oct 4, 2001)

What follows is an old post by Train that I kept that basically states that defrag should be the third step. See below:

Previously posted by Train:
Programs running in background For whom who asked the original question. I think you need a little more information, because you may be trying to defrag without having done a few other necessary steps first. Which could explain why it is taking so long. Defragging should really be a third step after: 
(1) deleting unnecessary files from your computer (what's the point of rearranging useless files?) and
(2) running the computer through a scandisk -[ which checks the surface for damaged sectors only when run in the thorough/ surface scan so that files are not put there in the defrag process.]
I wrote the following notes for colleagues at work, who knew nothing about disk maintenance, based on information gleaned from a number of websites and books. I hope you can get some benefit from them as well. *Step 1:* Deleting Folders and Files
*A.* Folders on the C drive from which all files can safely be deleted:
-> Windows \ Temporary Internet Files {deletes cookies including website log in info / payed to surf cookies if done using Windows explorer}[Deltree this directory from DOS does not effect cookies]
-> Windows \ Downloaded Program Files {contains files you may want to leave alone. Java, Activex applets that will be downloaded again when you visit the site again, addding time to load webpage. And windows Update site uses applets stored here.
-> Windows \ History
-> Windows \ Temp
-> Windows \ Cookies [Again payed to surf need these and Login cookies are here also.]
-> Windows \ Favorites (all can be deleted if you do not use Internet Explorer as your browser) 
The simplest way to delete all files in a folder is to highlight the folder in Windows Explorer, click the menu item EDIT>SELECT ALL, then hit the DELETE key.
*B.* Files (but NOT personal files) that can be deleted are selected on the basis of their extension i.e. the three letters that appear after the 'dot' and file name. 
Files which can be safely deleted are found in three places:
-> in Windows Explorer 
-> in email mailboxes
-> in your browser (e.g Netscape or Internet Explorer) 
Windows Explorer
In Windows Explorer, any file can be found by going to the menu item TOOLS>FIND>FILES OR FOLDERS. In the dialog box, type *.xxx, where xxx is the file type (listed below). The file types can be entered one at a time, or several at once, separated by semi-colons, for example *.gid; *.cnt. Specify the drive to look in (usually C), make sure the INCLUDE SUBFOLDERS box is checked, then FIND NOW. Note (1): The * is a 'wild card' and will allow all files with that extension to be found, irrespective of file name. Note (2): If you have any concerns about deleting a file, create a temporary folder (perhaps under 'My Documents') named DELyymmdd, where yymmdd is the current year, month and day. Move the files you are not sure about deleting to this folder, and if after experiencing no adverse effects for a week / month (depending on computer use) then delete the folder and its contents. File types which can be deleted, and what they are:
*.gid, *.cnt, *.ftg, *.ann, *.bmk
These files are Help sections, and will regenerate when needed.
*.avi, *.fts, *.diz, *.tmp, These files include How-To animations, files created when you do a search in a Help file, lists of files on previously installed programs, and temporary or old version of files. *.~??, *.??~, *.bk2, *.001, *.002 through to *.999
These are also temporary files
*.wav, *.mid
These are sound files, and you may want to keep them (say for PowerPoint). Most are junk 
*.zip
Delete these files after extracting the program files from them. If you feel unsure doing this,or want to, save the files to clearly labelled floppy disk, cd, zip or ??*.chk located directly on the C drive (C:\*.chk) but NOT those in any regular program folders
They are the result of running ScanDisk Mscreate.dir and/or a folder called ~Mssetup.tUnder the Windows Explorer menu VIEW>OPTIONS>VIEW, make sure the SHOW ALL FILES option is checked. Search the entire C drive for these two files and delete them. They are empty files created by Microsoft installation programs.
Because each email program is different, I will not try to give instructions on how to clean these up, but I am sure if you check your IN and OUT boxes, you will see which files can either be deleted forever, or zipped up and stored on floppy or another backup utility.
NETSCAPE
This is the browser I use, so this is why I can provide instructions for it. If you use IE or any other browser, someone else can provide the relevant details.
If you use Netscape to browse the internet, there is a lot of junk retained after each visit. To clear it out, go to the Netscape menu item EDIT>PREFERENCES. In the dialog box that comes up, click on Category>Navigator. On the RHS of the dialog box, under the section 'History Box', click on the button 'Clear History'. In the section beneath 'Location Bar History', click on the button 'Clear Location Box'. Click on the Category>Advanced>Cache menu, and clear the Memory Cache and the Disk Cache.
The next step is absolutely vital!
EMPTY THE RECYCLE BIN 
*Step 2:* ScanDisk
This program is built in to Windows and is designed to check for errors on the surface of your hard disk ('bad sectors') and errors in the files and folders, many of which ScanDisk can also fix. To make ScanDisk run at its best, no other programs should be running at the same time, and must be closed down. Many people do not realise that as well as the programs you choose to open yourself, a number of programs start automatically when you turn on your computer. These must also be closed down BEFORE you run ScanDisk. How do you know what is open? Pressing the three keys Control, Alt and Delete at the same time (C/A/D) will bring up a list of the programs running in the background of your computer. Not all programs should be turned off, otherwise the computer will not run at all. The two programs which MUST BE LEFT RUNNING are Explorer and Systray, all others can be closed down (one at a time) by pressing C/A/D, and choosing End Task. You may not recognise what some of these programs are, but invariably will include your virus checker - there may be several of these, checking incoming email, a random virus scan at startup, as well as continuous background scanning.
There may also be an MS Office toolbar. There is one other step to do before starting ScanDisk. You must turn off any screen savers. To do this, either go to Start>Settings>Control Panel, and open Display, OR right click on the desktop and choose Properties. You will get several tabs: click on Background, and set wallpaper to NONE, click on the Screen Saver tab and also set to NONE. To start the scan, Go to Start>Programs>Accessories>System Tools>ScanDisk You can choose Standard or Thorough, the latter of which you should choose if you have never run ScanDisk. Since it can take some time (up to a couple of hours), choose your time appropriately. If you need your computer before the scan finishes, it is OK to stop it, and start it again at a later time. It will take less time, as some of the scan has been done. However, because of the requirement to go through Step 1 - deleting unwanted files - should be done before running ScanDisk, it is obviously better to complete it in one sitting if possible.
*Step 3:* Defrag
When you create, move, copy, update, rewrite and delete files from your computer, they get fragmented. The computer can keep track of these fragments belonging to a single file, but it will take longer to display. To optimise computer performance, periodic defragmentation, or the process of reorganizing the contents of a disk so that all of a file's contents are written in a single contiguous block, is desirable. To run a defrag, which should be done immediately after running ScanDisk,
Go to Start>Programs>Accessories>System Tools>Defrag ------------------
and see http://www.putergeek.com/scandisk_defrag/

Hope this helps you. 

Let me start by saying this question comes up so often that I wrote this and saved it in a file to copy from, it's of course only my opinion. Right though.

I hope this post of Train's helps you.


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