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Why don’t you partition your hard disk so that programs are on C and data is on D?


Why have you never talked about using C: for programs only and D: for data?
And making an image of C so that any time that you get malware or other
problems you just format and replace the image?

In this excerpt from
Answercast #57
, I look at the reasons why I don’t recommend disk partitions as a
way to manage a hard drive.

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Separate C: and D: drives

Unfortunately, I’m not a big fan of that approach. I know that many people
swear by it, so this definitely falls into one of those “industry difference of
opinion” kinds of things.

You’re going to find a lot of people who believe that what you’ve just
described is a worthwhile approach to managing your hard disk.

In my opinion, it’s not.

The problems

In reality:

  • The division between your C: and D: (whatever you end up choosing it to be),
    it’s never really what you want.

  • If you’ve got malware on your machine, it is definitely not safe to assume
    that the only thing it’s going to affect is C.

It’s very possible that malware can infect any hard drive that’s attached to
your system. So if you end up reformatting and reinstalling from a backup of
only the C drive, you may be leaving malware on your machine on the D

As a malware prevention method, I don’t believe it really gives you what you
think it does and it might lead you into what I consider to be a fairly false
sense of being secure.

Space management

As a disk space management utility, again, I know many people swear by it. I
don’t. I just don’t see that big of a difference between doing it that way or
simply having a full partition.

My approach continues to be one partition per hard disk.

I simply don’t see a huge value these days of having multiple partitions
on a hard disk – simply because Windows now handles large hard disks just fine.
The NTFS file system does a great job of managing the amount of space and how
it’s allocated on hard disks regardless of size.

Ultimately, like I said, the reason why I don’t talk about it is because it’s
not something I believe in.

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23 comments on “Why don’t you partition your hard disk so that programs are on C and data is on D?”

  1. Along with using C: for OS and D: for Data with the price today it could be two drives I also use limited rights user. You say viruses will go through other drives but if there is a image with no virus you are one step ahead. As I have seen it the people that write the vires is always one step ahead of antivirus software and all the time virus software is worthless.
    The only reason radio tech people promote virus software is the $$$ from advertising.

  2. I find there is a considerable speed advantage in using more than one partition on a large HD.
    Faster OS defrags.
    Faster & smaller imaging of the OS.
    Faster searching for files.
    Faster malware scans.
    I use 3 partitions on my 1TB or larger HDs
    P1 for the OS.
    P2 for my extensive music collection
    P3 for Videos, movies & photos.
    This also allows for read only sharing of partitions 2 & 3 over my home network while keeping P1 private.

  3. one reason for partitioning –
    if you have c: (programs, etc), and d: (data), and you do regular backups, it is easy ot back up ALL of D:, keeps mirror image of data, as files (use a synchronizing or backup program)

    THEN, do an IMAGE backup of c:.
    if your drive crashes, you have easy file-type acess to d: files, and you have an IMAGE file of c: from which to restore to a new hard drive or to a reformatted drive.

    the d: data can be used on other machines if neded

    the IMAGE of the c: drive can be made as a VIRTUAL images, and has a smaller footprint than a combined c: d: image, and this image can be run as a virtual machine, on other machines, in event of disasters.


  4. I tried putting my user directory on a separate drive once but, when I went to upgrade to the next release of Windows, it said the upgrade couldn’t support that. That’s reason enough for me to keep my data in the same partition as the operating system.

  5. When Windows could not recognize large hard drives above a certain level, we were forced to partition but those limits are gone now. There is no good reason to partition any longer, and in fact, partitions can cause problems, particularly when upgrading the drive.

  6. grump3 is right. There are only advantages when you seperate the data from the OS. Everything else is just a bad excuse for a badly organized system.

  7. I’m with grump3 and nick. Putting data on a separate partition keeps the os partition small which results in relatively small image backups requiring less storage space. I back up D data files to a separate disk automatically. More than once I’ve restored C from an image and data is untouched. This strategy has served me well for years.

  8. In my experience windows accumulates crud and gets slow. So every couple of years I format C: and reinstall windows and the programs I use (in practice there are only about a dozen). OK it takes about a day including all updates but I have a clean machine.
    I arrange for My Documents, Firefox and Thunderbird profiles to be on D: so all my data survives the reinstall.
    And, as others point out, backup is easier.
    — Derek

  9. I’ve partitioned my hard drive before, and I always end up going back to only one drive letter. It’s a hassle trying to figure out what size you need, then it’s hit-and-miss to restore to the non-partition. I don’t see that it organizes the data any better. I had the same idea: Windows on C: and data on D:. But adding programs or updates sometime requires more room on the C: drive, so I’ve got to re-partition to add room. If you leave it alone, you don’t have to do that. It’s too bloody much work for little or no reward.

  10. It is highly unlikely that only 1 partition would be infected. Even separate computers on a network would be infected most likely. Seeing how there are thousands of viruses are eager to attack your system, any protection is better than none.

  11. My IBM X41 Thinkpad has a 32 GB SSD. I can only make C drive so small and D drive not as large as I wanted. Therefor I have to split my data between 2 drives if I want to make the most use of my 32 GB.

    I also thought that with Win 7, I could not create a data folder in the root of C Drive. I stopped using the “My Folders” ages ago because it can create huge file name strings. Putting a data partition in the root solves long file name problems.

  12. Dear Leo:

    I do partition my On-The-PC hard disk into “C:\” and “D:\”.


    Partition “C:\” is used only for storing operting systems and programs, and “D:\” is for storing data files, including those created by various programs (i.e. in C:\).

    I used to back up my system quite frequently, and as “C:\” is not loaded with data files, I could finish my back-up work (also restoring) much more quickly.

    If I feel my current system is showing sign of being polluted, I can also restore my system soely for “C:\” from a previous clean backup,
    followed by a virus-cleaning process to be done on “D:\”.

    Personal feeling : Running a virus cleaning software on a polluted “C:\” drive might result in some of the polluted softwares not workable totally / partially as in the virus-cleaning process, certain polluted software files might have to be deleted.

    Please do let me know whether my practice above make sense.

    Joe Lee

  13. I have read this article a number of times and still cannot decide for myself which is best.
    Leo’s arguments are very logical but the weakness of same is that he may be assuming that all are as diligent about PC health as he is. Speed is very important for a lot of people and there is no doubt that 2 partitions are a lot faster and easier to use.
    My own laptop does have C: and D(Data) and I have to say that I like it that way. Two days ago while experimenting with Anti Rootkit App’s my MBR went a little funny. To fix same took about a minute as I had the file backed up in D:. A quick restore and all was back to normal. I do of course have the MBR backed up outside the comp., but this would have taken longer.
    As to D(data) becoming infected, surely a good tiered AV system should be able to handle this, whereas with the OS there can always be problems. My image backups are also on D:, which is very fast. The only problem would be a HDD failure. But as my comp is over 5 yrs old should that happen I would just get a new comp. and restore all my external backups. I also have 3 sets of factory backup discs should anything happen to my present OS. The time required to restore my comp by this method would be 3 hours and 10 minutes as I have tested it.

  14. I agree with a lot of the readers and disagree with you Leo. Keeping my programs and data separate makes my life easy (on two drive C & D). I have separate backup schedules where I backup my data more frequently, and my programs less often, based on if anything has been updated. I agree with you about the virus problems. I religiously keep the system clean, and the two drive approach is definitely better than the “one drive for everything” approach. You may need to reconsider your position on this… Best wishes and happy computing…

  15. I do appreciate that with modern portable computers there are strong arguments against partitioning the hard drive.
    My main interest is in older desktops, however, and in that department I have found that adding an additional larger drive and keeping it for data only is an excellent method of upgrading. It retains the original system, but speeds it up by allowing system and data to be addressed simultaneously. It adds a lot of space for storage, and should the original drive be corrupted or die of old age, the data remains intact!

  16. If you are using only one operating system, then you should definitley have single partition on your hard disk. Take regular backup of your system and always feel relaxed. But if you are fond of having more than one operating system on your hard disk, then it does make sense that you should have corresponding multiple partitions.

  17. I like to keep separate partitions to reduce fragmentation. Temp folders and steam really like to fragment themselves, and I often throw around big piles of files. For most persistent programs(install once and leave it) and other stuff, keeping it all on one partition is fine.

  18. I partition for 2 things:

    a> speed
    b> image size

    a> using a 10 – 25% short stroke, (eg. 100GB – 250GB off the top of a 1TB HDD)
    and my SATA & EIDE HDD based systems can compete against the still currently way over priced SSDs with the same capacity as the allocated partition at a fraction of the cost

    b> using a small partition for OS & Programs only = small base backup image vs. a huge one that includes user files
    and with reference to “a” the image capture process is completed in fraction of the time it takes to do full base image of the entire HDD

    For all Data Disks I use single partition
    but for OS / Programs the performance improvements are worth the effort to make the partitions

  19. I like to have the data on a separate partition from the system, as it suits my restoring the system image every time the OS gets a bit messy. Wish I could do the same with the kitchen… I’d just have to remember to back-up the fridge.

  20. This argument has gone on as long as I remember (over a decade). Some users do and some don’t. It’s really up to personal preference and what you do and how much data you have. Personally, I choose to partition so I have at least two drives: OS and DATA. Faster defrags and smaller images are definitely a positive, too.

  21. Surley having more than one operating system is essential and that leads to LVM. its like everything else once you get the hang of it,its a doddle.

  22. The advent of lower-cost solid-state hard drives have added a new reason for two partitions. A 64GB or 128GB solid-state HD for the system C: drive. Then a second traditional HD for the data D: drive. Best of both worlds: blazing fast system drive and a large data drive.

  23. I used to partition my primary drive so the OS was in one partition, other programs in a second partition, and data in a third. This seemed to work OK, except when the OS needed to be re-installed. Then I had to re-install nearly all the other programs because many .dll files were loaded on the C: drive.
    I then just used two partitions; one for the OS and programs, and the other for data. The problem I ran into with that was having to re-size the C: partition because of updates and “improviements” of the OS and other programs, or because I added too many other programs.
    The best system – for me – is to keep the OS and all programs on a smaller drive – currently a 65G SSD – and use multiple HDs for the data; mostly externally connected. Now all drives only have the one primary partition. That makes imaging and backups a lot easier and faster, and still gives the separation I want.


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