Hi! On some Windows 7 machines I am getting the following error when I 
execute this code to enumerate all named pipes on a PC:

string[] pipeNames = null;
try
{
      pipeNames = System.IO.Directory.GetFiles(@"\\.\pipe\");
}
 catch (Exception ex)
{
}

ERROR:
System.ArgumentException: Second path fragment must not be a drive or UNC 
name.

Parameter name: path2

   at System.IO.Path.InternalCombine(String path1, String path2)

   at System.IO.Directory.InternalGetFileDirectoryNames(String path, String 
userPathOriginal, String searchPattern, Boolean includeFiles, Boolean 
includeDirs, SearchOption searchOption)

   at System.IO.Directory.GetFiles(String path, String searchPattern, 
SearchOption searchOption)

   at System.IO.Directory.GetFiles(String path)

I can not put my finger on what would cause some Windows 7 PC's crash and 
some work perfectly fine. It also works fine on Vista 

Any ideas/suggestions/help is greatly appreciated. 

Mike wrote:
> [...]
> I can not put my finger on what would cause some Windows 7 PC's crash and 
> some work perfectly fine. It also works fine on Vista 
> 
> Any ideas/suggestions/help is greatly appreciated. 

Based on the information provided, I would say that the "path2" argument 
to the InternalCombine() method is being set to something that looks 
like a drive or UNC name.

If you can get Microsoft's source server configuration to work, you can 
easily step through the .NET code that's causing the exception.  That 
said, I think ultimately you will find that the real issue is that 
you're trying to do something for which the GetFiles() method wasn't 
intended (i.e. enumerate named pipes).  Probably it just happens that on 
some computers, when the InternalGetFileDirectoryNames() gets tricked 
into trying to enumerate the named pipes, some pipe comes along with a 
name that looks like a drive or UNC name, hence the exception.

Since that would depend on what named pipes happened to exist at the 
time you executed the code, I could easily see the behavior varying from 
PC to PC, depending on configuration and the exact state of the machine.

Of course, only by debugging the problem would you be able to know for 
sure.  But I'm not aware of any promise on .NET's part that you _should_ 
be able to use GetFiles() to enumerate named pipes, so the real answer 
is probably just "don't do that."

Pete