Problem of periodical Windows Explorer hangs
Every windows user has experienced that the Windows Explorer sometimes hangs when accessing network drives of removable media. There is a kind of timeout after you can work again or in the worst case you have to kill it.I had this behavior on my notebook very often the last few weeks even when accessing local directories on my harddisk. My first guess was that it must have something to do with connected network shares because it did not happen when working offline.
I did a lot of web searches and then I came across this blog post of Mark Russinovich. There are many other articles around linking to this site talking about similar issues. Mark created some Windows tools for Sysinternals which was bought last year by Microsoft (see Wikipedia).
I did not need to use the Process Explorer to find out which process slows down my system. So I downloaded the Filemon and fired it up. After creating a filter that showed me only the Explorer process I was able to see every file access made by it. While working throgh the generated list I found something suspicious: There were many accesses to the shell32.dll and most of them looked in c:\windows\system32 for it - where it exists. The problem was that some of them tried to get it from other directories like c:\windows or my home directory. See the following screenshot:
When connected to the domain of my company the Z: drive is mapped to a share and defined as my home directory - this causes the explorer to search it for shell32.dll to and every time there is a problem with the network my whole systems is on wait.
I do not why the Explorer tries to search these directories for the dll file but it causes the hangs of my Windows Explorer. It seems to be a workaround to copy the shell32.dll into the windows folder.
Additionally I found some articles about the strategy how Windows searches for dll files. But it seems my behaves a bit different than described here in this MSDN article.
