You probably already heard that it is not recommended to install Windows 10 as your primary operating system, but if you really want to use it there are a couple of methods which will allow you to use it, along with your current system. And one of these methods is dual-boot. Performing a dual-boot is not a complicated task, and here’s what you need to do to complete it successfully.
Shrink Your System Partition to Make Enough Space
First, you’ll need to make space for Windows 10 on your hard drive. If you have two different hard drives in your computer and one of them is empty, you can skip this part. But you’ll probably want to install Windows 10 alongside Windows 7 or 8 on the same hard drive.
Before you install another operating system on your computer, you’ll need to free up some space for it. If you have two different disk drivers in your machine, and one of them is empty, you don’t need to do anything. But, you probably want to install Windows 10 on the same partition as your current system.
To free up some space for your new operating system, you’re going to use the Disk Management Utility, which is built-in feature in Windows 7 or 8. To run Disk Management Utility press Windows Key and R, and type diskmgmt.msc into the Run dialog box, and press Enter to launch it. Locate the your system partition, which is probably C:. Right click on it and choose “Shrink Volume.” This feature will free up some necessary space, you you’re good to install the new operating system on the same partition as your current OS. System requirements of Windows 10 Technical Preview say that you’ll need at least 20 GB of free space, same as for Windows 8 or Windows 8.1, but you’ll probably want to have more free space than that. After the shrinking is done, you can download Windows 10 from Microsoft’s website, and continue the process.
Also, don’t forget to backup your data before you install a new operating system. Although it shouldn’t delete any of your existing files, you should perform a backup, just in case.
Download Windows 10 ISO File
After you prepared your hard disk drive for installation of the new operating system, you should download it from Microsoft’s site. Download a Windows 10 ISO file and either burn it onto a DVD or make a bootable USB flash drive. After you do that, leave your DVD or USB Flash in your computer, and restart it. It should automatically start the installation, but if it doesn’t, change the boot priority in BIOS.
Install Windows 10 Alongside Your Current System
Now, install Windows 10 Technical Preview normally. Select your language and keyboard layout and proceed to “Install now.” After agreeing the license agreement, choose “Custom: Install Windows only (advanced),” because it will install the fresh copy of windows on your desired partition. If you choose “Upgrade” option, it will upgrade your current operating system to Windows 10.
The “Where do you want to install Windows?” will window appear. You’ll notice an “Unallocated Space” option, this is the space you shrinked earlier. Choose “Unallocated Space” and “New,” to create a new partition in the empty space. A Size box will appear asking you how big you want your new partition to be. You should use all the free space (which is also a default option), and just click Apply to create a new partition.
After that, just follow further on-screen instructions, and finish the installation.
Choose Which Operating System You Want To Boot
From now on, you’ll be able to choose which system you want to use on your computer. To switch between Windows 7/8/8.1 and Windows 10, just restart your computer and choose again.
Go to “Change a default operating system” or “Choose other options” in order to choose which operating system you want to boot by default, and how much time will pass before the computer automatically boots the default one.
Both versions of the system use the NTFS file system, so you’ll be able to easily access your files from both operating systems.