Question : How to add Macbook Pro to PC's Local Network?

I have a Macbook Pro (OS X) that can see my PCs on my Local Network.
But when I am using my PCs, I can't see my Macbook Pro on my local network.
How to add Macbook Pro to PC's Local Network?

What I've done:
- Allowed "file sharing" on my macbook pro under Sharing window.
- All coumputers have wireless internet via a home wireless router (linksys)
- A local network established between 2 PCs.

Answer : How to add Macbook Pro to PC's Local Network?

Also need to enable Windows File Sharing:

Go to System Preferences/Sharing.
click on File Sharing and then select 'Options'
Check "Share Files and Folders using SMB"
Select the accounts you want to be able to do this.
Click "Done"