One: It's better to check whether official website has a driver. If there is no driver, you can only use a compatible driver, and there are many minor problems.
Two: It is recommended to back up the original system before changing it. Otherwise, it will be troublesome to use the original system in the future.
Thirdly, the BIOS boot mode UEFI is changed to Legacy, and the hard disk partition mode GPT is changed to MBR.
Four: You are the latest model, but you should consider these two new situations:
1:do you need nvme driver for the hard disk under win 7? Some Lenovo new machines use Samsung SSD, and this driver is needed under win7. In this case, it is necessary to install the ghost version or the system installation version integrated with NVMe driver (the installation version can be a NVME driver USB flash drive, and the driver is loaded according to the prompt when installing).
Whether USB interface only supports USB3.0 interface. The USB of the 6th generation CPU is version 3.0. If the keyboard can't be used when installing win7, you need to install the ghost version or the installed version system with integrated USB3.0 driver.
3. 1 and 2 occur at the same time, so it is necessary to integrate the ghost version or installation version of the two drivers.
Five: modify the bios boot mode and partition mode.
1: Change the boot mode UEFI of BIOS to Legacy.
(1) safety project:
Safe startup, change enabled to disabled.
(2)② startup:
Change the boot mode to legacy priority, legacy support, or automatic.
The startup priority is changed to traditional priority, traditional support or automatic.
Enable CSM(CSM support) to enable (if any).
③ Exit the project:
Boot the operating system (operating system optimization default)? Select a different operating system (disabled).
Press F 10 to save and exit.
2. Plug in the USB flash drive, press the novo key to boot, select the boot menu, then select the UEFI+USB flash drive model, and press enter to boot. After entering the desktop of PE system, call any disk tool, such as diskgeniu or partition assistant, to convert partition GPT into MBR. These two tools are basically the same.
① Call any disk tool to convert partition mode GPT into mbr.
Open the partition assistant, select disk 1 or disk 2 (the hard disk to be converted) at the lower right, and click the right mouse button to convert it into MBR disk.
Open diskgenius, select the hard disk model on the left-click the right mouse button-and convert the partition table type to MBR format.
② rewrite the boot area at the same time (rebuild MBR)
Open the partition assistant, select disk 1 or disk 2 (the hard disk to be converted) at the lower right, and click the right mouse button to rebuild MBR.
Open diskgenius, select the hard disk model on the left-click the right mouse button-and rebuild the master boot record (MBR format).