Win7 uses the restore function to retrieve the lost system files.

1. First click the computer option on the desktop, wait until the pop-up box is selected, select the system property option inside, and then directly click the system protection option on the left;

2. Select the disks that need to be protected. Of course you can turn them on or open them individually. Take the D drive as an example. After selecting it, click the configuration option below, then select the option to restore the previous version, then adjust to The maximum amount of usage, then click & ldquo; OK & rdquo; to close.
3, then click on the Create option, create a restore point so far, enter the backup name in it, and then click OK.
4, open the computer, open the D drive, right click on the drive letter, directly select the properties to restore the previous version, then you find that you can restore the backup version.