1) Click Start.
2) Programs -> Accessories -> System Tools -> Scheduled Tasks

3) Click Add Scheduled Task
4) A wizard will show, click Next until you can see programs and there is a Browse button.

5) Click the browse button and look for system 32 (usually in C:\WINDOWS\system32)
6) Find shutdwon.exe
7) Choose your desired option, whether it could be daily, weekly and the time you want it to run.

8) Follow the next options and Click Next until you will find Finish button.