Make a 2 way sharing folder with my PC
If the folder is shared from Windows and is accessible from other Windows machines then it should be accessible from your Mac as well. There are two possible causes to the problem you are describing:


You are using OS X 10.8.0 and you are trying to connect to smb://&lt;machine&gt; instead of smb://&lt;machine&gt;/&lt;share&gt;. If this is the case then the solution is to connect to smb://&lt;machine&gt;/&lt;share&gt;.
You are using any version of OS X and you are trying to connect to smb://&lt;machine&gt;/&lt;share&gt;. If this is the case then you probably aren't entering the username correctly. On your Mac when connecting to a Windows file share you should try entering the username as WORKGROUP\&lt;username&gt;. (Case may matter)


NOTE: I got into the habit of always entering the username in that format way back in OS X 10.3 (maybe even earlier.) It could be that it is no longer required, but it has never failed me, so I just stick with what works.