Set my computer back to factory now Windows update

OK, my son used my laptop and crazy stuff started happening including a CMOS warning when I turned on the computer. I deleted everything he had downloaded and returned to factory condition. Now Windows update doesn't work and when I try to use the troubleshooting, including direct from Microsoft download, I get this weird message. A problem is preventing troubleshooting from starting. Package id unknown, path unknown, error code 0x80070002, source engine, user me, context restricted