Unable to start computer

Hello, While trying to restore to an earlier date machine froze, had to restart. When it retarted got many messages all with the same wording, this application failed to start because iertutil.dll was not found, reinstalling application may fix this problem. Not only did that message come up but the same for services.exe, lsass.exe, userinit.exe, explorer.exe, and taskmanger.exe. The machine will not start in safe mode will only give a blank screen with safe mode at the corners. Regular start up will only get background no icons. Can anyone please help, I really need this machine to work because both wife and daughter have school work to do.