Installing Ubuntu dual system on Win7 without a USB drive. This article tests the installation of 64-bit ubuntu-18.04.2.
Preparation#
- Win7 system
- Ubuntu system image file
- easyBCD
Step 1. Partition the Hard Drive#
Right-click on the computer, select Manage, go to Disk Management, and use methods like compressing volumes to obtain the partition for the Ubuntu system. Alternatively, if you already have a partition for Ubuntu, delete it. 
In Disk Management, compress the C drive and then format the compressed free space as FAT32. The compressed 5GB space will become the F drive. Move the ubuntu-18.04.2-desktop-amd64.iso and the vmlinuz and initrd files in the casper folder of the image file to the F drive. 
Step 2. Use EasyBCD to Boot Ubuntu ISO#
Open EasyBCD, add a new entry, select NeoGrub, and install it. Then click Configure. In the menu.lst that appears, enter the following content at the end:
title Install ubuntu-18.04.2 root (hd0,1) kernel (hd0,1)/vmlinuz boot=casper iso-scan/filename=/ubuntu-18.04.2-desktop-amd64.iso ro quiet splash locale=zh_CN.UTF-8 initrd (hd0,1)/initrd
If the txt text box does not pop up, you can find the menu.lst in C:\NST and open it with Notepad.
Step 3. Restart and Select NeoGrub#
Before installation, open the terminal (Ctrl+Alt+T), enter sudo umount –l /isodevice, with a space before and after the dash, and execute it multiple times to ensure that the mounted image is removed. Otherwise, installation will not be possible. 
Step 1#
Double-click the "Install Ubuntu" icon on the desktop, wait for the "Welcome" panel to appear, check if "Chinese (Simplified)" is selected on the left sidebar, if not, select it on the left, and then click the "Continue" button in the lower right corner.
Step 2#
Check the preparation status, make sure there is enough disk space, do not connect to the internet, generally do not select updates and third-party software, directly click the "Continue" button.
Step 3#
Ask which partition to install, select the "Something else" option at the bottom, and click the "Continue" button.
Step 4#
Next, the disk partition situation will appear, and the free space is the volume we deleted at the beginning, which is the hard drive where Ubuntu will be installed. Click to select the planned installation partition, and determine based on the partition type and size. I have 220GB of space, \boot 2000M, swap 3G (swap space, same as the size of the memory), \home 15G, and \ is about 15G (of course, if there is enough space, you can divide it more, /boot can be 2G, swap follows the system memory, whatever the size of the system memory is). I divided 15G for / and allocated the remaining space to /home. When partitioning, select 'Primary' for /boot and /, and 'Logical' for others. In the dialog box that appears, set the format for the partition to Ext4, check "Format", click on the right side of "Mount Point", select "/", and click "OK". Note that formatting will delete all files on this partition, so please backup important data in advance. Only swap is used for "swap space", the others are used for "Ext4". After partitioning, click OK (note that the bootloader (grub) should be installed on \ or \boot, so that when the Windows system is reinstalled, it will not affect the Ubuntu system), and continue with the installation. Ubuntu installation is complete.