This tool will allow you to configure the account database to enable additional encryption, and protecting database from compromise.

So try following steps to enable this encryption:

1. Click on start menu.

2. Then click on run icon.

3. In run menu type syskey.exe and click ok.

4. Click on update.

5. Then select the password setup.

6. Enter the password and confirm it.
Now you are done.

Note:Once enable this encryption can’t be disabled.