an unfamiliar folder ???

[Beyond_Life]

It could be a folder that is protected by some program so you are unable to delete it. It could damage the program thats using it. If you right click it, and choose properties, what does it say? Maybe you can find out for wich program its made.

[Austin]

recently, I find an folder which have "a lock" in the folder leftside, what is it? why it occur? how can I remove it?

 

Where is this folder located? It could be an operating system file, or it could be a folder locked by windows in the user profile.

 

Regardless which folder it is though, you can likely take control of it and remove it using the tool in this article:

http://www.groovypost.com/howto/microso ... s-folders/