I want to install dual OS on my system. I never done this and have some queries. I have a 500GB hard disk I want 3 partitions.

  1. for Windows OS (100GB)
  2. for Ubuntu (100GB)
  3. extra partition which is accessible from both OS.

My questions are the following

  1. How to install dual OS? Should I install Windows or Linux first?
  2. Is it possible to share a common partition in both OS? How?
  3. I have an .ISO image of both OS's, can I install directly from them without writing it to a DVD or pendrive?
  4. What format should I use, NTFS or FAT32 or some other? (Both OS's are 64-bit)
  5. Are there any drawbacks? Like performance, or any other?
  6. Is there any proper calculation to set a partition size? A friend of mine always does some calculations before creating partitions for better HDD speed and less waste.

Please, if possible give me links to some good tutorials.

6 Answers 6

  1. you have to install windows first, else window will remove the boot-loader of ubuntu.
  2. yes, you can make it NTFS or FAT32.
  3. you have to write it on dvd or pendrive
  4. for ubuntu you can not use fat32 or NTFS, use ext3 or any other format.
  5. no, only boot time will increase
  6. no, it will be your choice, generally for swap partition you can use 2*RAM Size.
  7. you can google it.
  1. Usually best is to install Wintendo first, then Linux. Best is to install the Linux Bootmanager (Grub in most cases) into the MBR of your disk and configure it to chainload Windows. Most Distros should do this automatically. And most Distros have rather good documentation for installing parallel to Windows.

  2. You should use a filesystem that both Windows and Linux can read and write for your "sharing partition". This would be NTFS or FAT32.

  3. Usually no.

  4. I'd prefer NTFS, since FAT32 isn't really a file system. ;) But you should be careful when writing files from Linux on the NTFS disk, since NTFS allows much more characters in file names than Windows can cope with (e.g. you should avoid using things like : in file names, since Window would choke on them). Edit: You shouldn't use one of those for the partition your Linux is installed, therefore the explicit mentioning of "sharing partition"

  5. Usually no.

  6. In the old days™ it was a good idea to have partitions on cylinder boundaries, but nowadays the correlation between what your OS thinks your HDD looks like and what your HDD really looks like physically is entirely virtual.

  7. Aunt Google can tell you.

  • So NTFS for both windows and file sharing partition and ext3 for linux? Usually shared partition is for store files thats it so I can access from both os. Mar 24, 2014 at 10:06
  • Exactly. That's the way it's usually done. Mar 24, 2014 at 10:13
  1. Installing windows first will be good..
  2. Yes, while partitioning, create 3 partitions and install Windows in a partition. Install linux on any other partition and the other one will be available on both.
  3. Where you have ISO image if it is not currently available in DVD or pendrive??
  4. NTFS will be good. In linux it will be good to use ext4
  5. Ofcourse, performance will be impacted. Depends on your PC configuration.
  6. https://askubuntu.com/questions/149844/partitioning-hard-disk-for-dual-boot http://en.wikipedia.org/wiki/Multi-booting
  1. You should install Windows OS first. Also, if installing multiple Windows versions, install oldest version first and proceed to newest one (First XP->7->8->8.1)

  2. Yes it is possible to share common partition between both OSs. Just make sure you format that partition with NTFS or FAT32. Do not use exFAT file system.

  3. No, you cannot install OS directly from ISO image. You must use bootable disk or flash drive for the same.

  4. For Windows OS use NTFS and for Ubuntu use ext4.

  5. Absolutely not. At any time only one OS can run on machine. So there wont be any performance setbacks. Just make sure you create a SWAP partition (usually twice the size of your machine's RAM) for Linux distro.

  6. Partition size depends on your usage. If you want to install large applications like Visual Studio or heavy games on Windows, and if you insist on installing everything on C:, then you should create large partition for Windows OS. I think your friend does the calculations simply to convert from GiB to MiB since in OS setups we have to enter partition size in MiB. :-)

  7. Actually there are plenty of tutorials available online. If you simply Google for it, you will find them. You'll have to choose one of them depending on the depth of detailing they offer.

  1. I think it is easier to install windows first.
  2. It is possible. Ubuntu can use NTFS partitions.
  3. I think you can extract windows iso into folder (using 7zip) and run setup.exe from there. It will work in most cases. I don't think it is possible for linux
  4. FAT32 partition is limited to 32GB. So you should use NTFS for common partition.
  5. NTFS permission won't work in linux. Performance will be slower in some cases.


  1. Windows first (second answer,by devesh, says why)
  2. Ubuntu can read any format Windows can but I think Windows can't read ext3 or ext4.
  3. Ubuntu expects to install from DVD or pen drive, don't know about Windows
  4. See 2.
  5. Drawbacks? Slower boot (because it gives you time to make a choice of OS). Otherwise only what you would expect from having less HD space available for the OS than the full 500Gb.
  6. You should consider having a separate swap partition for Ubuntu.
  7. Favour tutorials from Ubuntu sources. Most contributors will have actual experience of this, whereas a Windows source may only be a secondary source.

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