How to lock your PC after a password error
If you’re worried about losing data from your computer through someone logging in as you, then you can always set up to have your PC request a password, then lock-up after three failed attempts.
First, you need to locate the Local Security Policy menu, by opening the Start menu and searching for the term. Then, double click on the Account Policies folder, and then the Account Lockout Policy.
Then, you’ll need to click on the Account Lockout Threshold entry. A dialogue box will appear, requesting how many times the password needs to be entered incorrectly before the computer locks – set it to “three”.
You will also be able to set the amount of time your computer will be locked out for. Setting the lock down for 30 minutes is usually a good enough time.
This option won’t make your computer completely safe from people trying to guess your password, but it will make the process a little more difficult.