For your secure you can add password, whenever some of us use sleep mode, but sleep mode just for stop computer work and quickly can resume.

This is some step for made password sleep mode
1. Going to control Panel > hardware and sound > Power Options.
2. choose select a power plan
3. active Require a password and type your password.
4. click ok if done.


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you can also set the expire password for your computer. this step setting for password expire and when expire you can change the new one.

1. from start at the search key type local security policy
2. then go to account policies > password policy and choose maximum password age
3. open maximum password age and you can input password will expire in...many days.
4. after that click oki for confirm.


Hope that use.