XML Save Error

[Jim]

Hey all, if anyone can help with this I would appreciate it. I'm
loading an XML file and modifying one of the nodes. Once I modify the
node, I call the .Save method on the XML document object and I keep
getting the message below:
The process cannot access the file "C:\Documents and
Settings\xxxxx\Desktop\Code\Test\Config.xml" because it is being used
by another process.
Any help in how to get around this would be appreciateed. I've even
tried rebooting my PC and I still get this message.

Here is the code that I'm running:
'load the xml file
xdConfigFile.Load("../Config.xml")
'get the value
Node = CType(xdConfigFile.DocumentElement.SelectSingleNod e( _
"/config/chat/chat_name"), Xml.XmlElement)
If Not Node Is Nothing Then
'set the node info
Node.InnerText = strComputerName
Node.InnerXml = strComputerName
End If
'finally, save the new version of the config file
xdConfigFile.Save("../Config.xml")