how to open password protected files

Hello, I have just installed BitDefender on my laptop. My first scan picked up loads of issues with Rootkits in hidden, password protected files. The help info says to open these files and run the scan again, but I don't know how to open them. Can you help please? The laptop is running very slow and often freezes.

This is a copy of what the help info says:-
HomeSupportPassword protected items
Password protected items
Issue:
When scanning with BitDefender, you may come across some items that are marked as "password-protected", which BitDefender reports as potential threats


Solution:
In these cases, BitDefender is simply notifying you that it was unable to scan certain password-protected or otherwise encrypted items, due to the fact that a password or encryption key is required to access the contents of the archives/files that are listed. In order to scan these files with BitDefender, you will need to unlock these archives/files with the password that was used to protect them, or otherwise decrypt them using Windows Explorer, or another proprietary decryption method.

Regardless of this notification, BitDefender's real time protection will still block access to any infected file that may attempt to run on your computer and take the necessary actions to disinfect/quarantine the file.


Thanks