This operation is similar to that of winXP. Method 1: Press F8 before the Windows system home screen is started. Method 2: press CTRL when you start the computer. You can select "SafeMode" to directly access the security mode. Operation guide in Windows 7 Security Mode 1. when deleting stubborn files in normal Windows mode or clearing the recycle bin, the system may prompt "the file is in use and cannot be deleted ", in this case, we can delete it in security mode. In safe mode, Windows Automatically releases control of these files. 2. System Restoration in safe mode if your computer cannot be started now, you can only access the latest computer operating system download safe mode, then you can recover the system in safe mode. After entering the security mode, click "start"> "All Programs"> "accessories"> "System Tools"> "System Recovery" to open the system recovery wizard, then, select the "Restore my computer to an earlier time" option, click the "Next" button, and click the date displayed in italic on the calendar to select the System Restore origin, click "Next" to restore the system. 3. virus detection and removal in security mode the update speed of anti-virus software cannot keep up with the pace of the virus. Your computer will be infected with the virus. However, many viruses cannot be cleared in Windows, but anti-virus software cannot run in dos. At this time, we can start the security mode. In Windows, only necessary drivers are loaded, so that the virus can be completely cleared.