Win8.1 how to install win10 dual system

First, prepare for work
a) Create a new installation partition for Win10
First we need to prepare a pure disk partition for the next Win10 preview installation, here I teach How do you create a new partition directly in the Win8/8.1 system, as follows.
1, first enter the Win8.1 computer management, we click on "Disk Management", then we need to find a partition with a large remaining space, right click on it, select "In the pop-up menu" Compressed volume, as shown in the following interface diagram.

disk compressed volume
2, the pop-up dialog box compressed volume, we need to enter the compression space. Since the author chose the F disk of 300G capacity, it has already used 20GB, and the remaining 280GB capacity is available. Here is used to install Win10 system, and Win10 installation disk, Win10 system disk space is generally recommended to reserve more than 30GB capacity (Pepsi network PC841.COM original tutorial), here Xiaobian to assign it 60GB, which is 60 * 1024M = 61440 (M), after entering this capacity, click on the "Compression" at the bottom, as shown below.

3, this time, this new partition is not yet available, here we also need to create a simple sub-volume. Methods of operation are, right on the new partition, and then select the "New Simple Volume", as shown below:

last all the way to complete the next step, after the completion of the new partition Win8.1 us into my In the computer, you will see a new hard disk partition, this partition will be used as the Win10 system installation disk, as shown below.

b) Win8.1 and Win10 dual system installation began to prepare
1, first download the latest ISO Win10 system image file format in 8.1 computer;
Note: The system of Win8.1 and Win10 The number of digits should be the same. For example, if our Win8.1 system is 64-bit, then you must select 64-bit if you download Win10 system. If the number of double-system digits is different, the installation will go wrong. This requires special attention.
Since Win8.1 and above can open the ISO image file directly, we can directly double-click the downloaded ISO image file to run, and then we will enter the DVD drive directory. Then, in this case, we will enter the "sources" folder as follows. The figure shows.

into the sources folder