Fdisk information

This is an attempt to direct people to more specific fdisk help/utilities. If you know of others then feel free to msg me with your suggestions. Please note that none of the places are affiliated with fdisk.com.

I often get questions about the DOS program FDISK. I don't mind the questions and I know a fair amount about partitioning drives. Just be aware I had nothing to do with creating the hardware or software involved with the process and you are on your own if your data goes *poof*. If you want certified help then call the company that made the hardware--hardware companies are usually very helpful.

If you were looking for some walkthroughs or someone looking for questions to answer, try 5starsupport.

Also available is Radified FDISK Guide to Partitioning a Hard Drive

Microsoft Help:

  • How to partition and format a hard disk in Windows XP
  • How to Use the Fdisk Tool and the Format Tool to Partition or Repartition a Hard Disk
  • Using debug to wipe partitions.

    Can I repartition my hard disk into one large partition without loosing my data? It isn't as simple as it might seem. Any applications not on the C: drive will have references directed at the old location. They won't work very well once you move them. Its also more of a pain then it might seem to change the number of partitions on one drive. Basically, if you don't already know how to do it then you would be better off just backing up your data and starting over with a fresh install.

    This debug script (from Bill) and a win98 boot disk will wipe any drive of its pointers letting you start with a clear table. This should help if your drive is so messed up that fdisk complains that it can't deal with the drive information or crashes. Alternatively, if you'd rather not contend with assembly language commands and DEBUG, a simple program called 'Partition Zapper' is available at http://www.meixler-tech.com/pzapper/ which will clear the partition table in a few keystrokes (cost: $12).

    If your fdisk is having problems or you are in need of a copy, you can get the Free(DOS) Fdisk which is now ready for prime time and supports many features not even in the standard DOS version. This can also handle many partition jobs that regular fdisk fails on.

    Tom Kuurstra and Joep van Steen of DIY DataRecovery have created a number of tools to help people recover data, search or modify hard drives and edit or save MBR information. One tool can even modify saved MBR copies. They are also willing to help people personally as long as you treat them with respect and provide the information needed to help you.

    HDD provides disaster recovery solutions for an accidental format, accidental fdisk, file recovery. Before and after the event.

    Diskman is another up and coming disk recovery, backup and manipulation tool by James Clark. "Mount and manipulate disk images" sounds like a tasty option. ZhanFeng also makes something called diskman, but everything is in Chinese so I have no idea what its deal is.

    If you happen to get the CIH virus, here is a program that can potentially recover your data. I haven't tried it yet as I don't have a CIH infected computer. Also, remember that you should turn back the BIOS date on the infected computer to early 1998 before fixing it and scan/disinfect right after recovering because the virus may still be there! Good luck. Here is another free recovery tool at grc.com.

    There are some handy disk utilities at simtelnet especially in the bootutil and diskutil areas. You can also use their excellent search to find other tools.

    You could also look around http://www.bootdisk.com/ and they might have something to bail you out of a jam. PCHelpLIVE.com also has a booting soltion for people in need as well as other PC help stuff.

    If you are looking for a technical description on the subject of partitions, check out Partition Tables - Focus on OS/2 - 09/02/98. If you dig reading then PC Guide's enormous Hard Disk Drives reference section is sure to interest you.

    If you are looking for a tutorial on partitioning your drive, try Weendoggy's Homepage or Microsoft Support on How to Install Windows 98 on a Computer with No Operating System. Dan's Data has a good page on Upgrading your hard drive.

    Computer Hope has a very nice online simulation of fdisk available for people to fool around without chance of blowing anything up. They also have some more information about the command line switches and such.

    Wondering what the Volume Serial Number is all about? Check Brett Glass's site and he will clear it all up.

    Old hard drive specs can be found at TheRef and Blue Planet.

    People who badly need to recover their lost/deleted data should try Lost and Found by Powerquest. You have to buy it to get your data restored, but I have been told it is very successful and also easy for novices to use.

    If you want a supported product for resizing disk partitions then you should check out PartitionMagic or Partition Commander.

    If you are willing to live dangerously, there is a free program called FIPS that can do nondestructive splitting of harddisk partitions. It does not join partitions. I have used it once or twice in the past and it worked great, but I URGE everyone to read the directions before trying it!

    The Partition Resizer is one I haven't tried, but it looks promising.

    The Randish Partition Manager site hasfree software that can manipulate/save partitions as well as a boot manager. It also has a primer on partitioning and some other great information. I have not tried the Ranish Partition Manager yet myself.

    Here are some links that people sent me:

    Yaru pointed me to http://how.to/use_Partition_Doctor. It is both the download location and instructions on using Partition Doctor, a program for inspecting your partition table for errors and fixing the correctable ones. He also has some good partition site links.

    Andrew sent over a link on Dr Solomon's anti virus web site that says not to use FDISK /MBR to kill viruses. I don't agree that you should never use it, but it was a good read anyhow.

    Robert sent me the following link that contains a few more fdisk switches then I have: http://www.jacobsen.sdn.dk/fdisk/ Undocumented FDISK. He also has a good install info page for win95 and some good utilities off his main page.

    Alan found a great link at Maxtor that covers hard drive capacity barriers, so (for instance) if you don't understand why you only see 8.4 gig of your new 12 gig drive then check that out! 528 MB, 2.1 GB, 4.2 GB and 8.4 GB limitations are covered. One thing to note, however, I got a message from Kat that said when she installed a new drive with Maxblast's EZ-BIOS many applications didn't function properly. I have no idea if it was a bios problem or if apps really don't like the disk managers, but it is something to watch for. Anantya sent over a link to Seagate's info on hard drive capacity barriers. They also have a downloadable copy of their diskmanager if you have a Seagate drive that you can't get you computer to fully utilize.

    http://www.compguystechweb.com/ has some good information on drive problems and a separate fdisk help section too.

    Ghostsoft: They make a nice disk clone tool that uses a text interface or just the command line.

    HDCopy: Apparently a HD copy utility company, but I know nothing about them.

    Gibson Research Corporation: They make the SpinRite utility for repairing drives (Yes, it still exists!). If you have an IOMega Zip or Jaz drive, you might want to check out their Click Of Death Research Resource Page which has a test for the problem.

    MasterBooter makes a companion program to their boot manager called EFDISK. They say it can be completely driven from the command line! Untested by me.

    Someone sent me an FDISK.HLP.zip Windows help file for FDISK. I didn't even know that one was available!

    Walter mentioned an old dos utility called delpart that can be easily found via web search which can wipe ntfs and other sticky types of partitions. It can be found in the file systems section of the (very nice) SavillTech NTFAQ site which has all sorts of good NT stuff.

    If you are looking for information on NT file systems, check out the file system section of http://www.ntfaq.com/. Walter turned me on to them when he introduced me to the delpart program for getting rid of sticky partitions. It is still there, but now I recommend the infamous debug script instead.

    Somebody from Codework sent over a link for RapiDeploy, an imaging/cloning tool that can personalize each pc as it is cloned.

    Here is an interesting link to Circuitmasters HD tech page sent over by a third party (Roy). They have some interesting info about drives as well as other hardware too.

    Ken over at ACR Data Recovery Services says that a few of my visitors told him to ask for a link. He has software that is used for repairing boot sectors and partition tables for DOS, Win95/98 and WinNT/2000 (FAT16, FAT32, NTFS) formatted hard drives and removable media. Sounds like good stuff! Check it out at http://www.atl-datarecovery.com/bp.htm.

    If you want to pay someone to recover your data, http://www.averdrivetronics.com is one company that will do it.

    If you are looking for raw info about drives and stuff, PC Guide has some fantastic info up in their Hard Disk Drives section!

    I received a nice e-mail from a person named James that I thought I would pass on. It contains a bit of info that may help others:

    I had a problem which I have never seen before and I been a systems administrator for about 5 years. I had this 4.2GB Fujitsu drive that I was trying to clear off. It had a primary partition, and an extended partition with no logical disks specified. I tried to delete the extended partition but I kept getting an error saying that I couldn't delete the extended partition with logical drives existing. So I try to delete the logical drives, but there aren't any. So I was stuck on it for an hour. I got desperate and decided to surf the web. I would a site that had very little info but had just what I needed. The site specified that there are undocumented switches that work with FDISK. I already knew that there was an /MBR switch to repair the master boot record, because I has to use it many times. I found much more! I was able to force fdisk to create a logical partition from the command line, Then I was able to delete the logical, extended, then finally the primary partition. I though that you may find these useful and could possibly post them on your site for people like me that happened to surf in to find hard to find info. Here they are:

    Undocumented or little known FDISK parameters:
    FDISK 1/PRI:100 - Command line to create a 100 meg DOS partition on hard 
    drive 1.
    FDISK 1/EXT:500 - Command line to create a 500 meg extended DOS partition 
    on hard drive 1.
    FDISK 1/LOG:250 - Command line to create a 250 logical drives.
    FDISK /STATUS - Shows you the current status of your hard drives.
    FDISK /MBR  - Repair the master boot record.
    FDISK /X - Ignores extended disk-access support. Use this switch if you
    receive disk access or stack overflow messages.
    John McDonald clarified the /q switch:
    FDISK /Q - prevents fdisk from booting the system automatically after exiting fdisk.
    Kim Rickaby has seen this as a result of DOS/Win95 incompatibilities:

    What it turned out to be is that I was booting to a 6.22 floppy disk and running fdisk. Fdisk would see the primary and extended but would not let me delete the extended as it believed they was a logical partition which I could not see. However the problem was cause by the disk had been setup by Windows OSR2. When I booted of a floppy that had OSR2 and the Fdisk program for it I was then able to see the logical partition and therefor could delete it.
    Ted Fines had some additional information to share about this problem:

    If you have OS/2 on your system and you create a boot manager partition, you'll find that you can't get rid of it with DOS FDISK. This may be what happened to James.

    To get rid of the unwanted partition, one has to either reinstall OS/2, use an OS/2 boot disk with the OS/2 FDISK utility, or...

    If the BIOS has a format hard disk utility, it will wipe out the OS/2 partition. Otherwise, try to mess up the hard disk even worse than OS/2 has. Use Norton Disk Doctor to hose up the FAT and Partition table. Then, you'll be able to use DOS FDISK, since it will just see your drive as garbage (as an unformatted drive).

    I advise being careful with the BIOS format utility. Some of those are low level formatters and that is not recommended by at least some HD manufacturers any more. Better to screw up the drive with a disk doctor, or get a better fdisk than DOS's (some listed above).

    Ryan sent in a nice chunk about scripting fdisk.

    Bob pointed out that a Linux rescue/repair disk will have an fdisk capable of wiping almost any partition. I would bet that freebsd also has one too. I have omitted this info in the past due to the learning curve, but I guess people are ready now.

    There is even more interesting fdisk information at MS-DOS Hidden Secrets. It also has secret switches for other DOS commands.

    Marian Hubinsky sent over ata.exe which I have zipped up. It is a program which shows connected ata compatible devices. It supports 4 ata ports and shows detailed info about hard drives and other stuff.

    http://help-site.com/ has a lot of OS help.

    A quick tip from Kevin for people having trouble with KG7-RAID boards:

    I made a 98 boot disk; booted the machine to it with cd support; checked the I386 file on the cd-no probs there. I then ran winnt.exe; it told me the disk needed to be formatted; i ran fdisk the machine said there were no fixed disks. I then checked jumper on hd-it's set to master. Cable is correct plugged into ide1. Bios sees it.

    And his self-found solution:

    The WDC hard drive needs to be jumped 4&6 (neutral).

    That's all it for now.