After removing the partition, installing Win7 can not start "Starting interface security mode card in disk.sys"

Scope of application:
ThinkPad, pre-installed Win8, pre-installed Linux, Win7
Knowledge point analysis:
Pre-installed Windows 8 or Linux system modified Windows 7 will appear in the Windows interface or safe mode card Loading the disk.sys interface.
Normal startup as shown below:

Security mode as shown in the figure:

Most of these problems are caused by the partition format not successfully converted into MBR format, please backup the data, use Pure installation version of the installation media, you can use the command conversion format.
Operation steps:
The solution is to use the DiskPart tool to repartition.
1. Use Windows 7 CD or U disk to boot, enter the system installation interface;
2. Press Shift+F10 or Shift+Fn+F10 on the interface to select the command prompt;
3. Enter the following commands in CMD, and press Enter every time you enter a line;
diskpart
select disk 0
clean
convert mbr
exit
4. Turn off CMD Window, refresh repartition, reinstall the system.