I have problem with my windows 7. When i try to open a directory on LAN, every now and then it begins to reload the directory. The upper bar begins to fill up with green color (in my theme of course), and it takes very long time, like 3, or 4 minutes. In the directory there is not much stuff, maybe 200 or 300 text files. And during this 3 or 4 minutes, the computer is almost blocked. It is very slow, the browser can not connect to any site on internet, any programs that are working stalls, or becomes very slow. When the directory is loaded, things return to normal. And what is more, this problem does not occur with every directory on the LAN, only with some of them.
What can be the reason and how can I fix it?