Hello, By default right-click on a file in Windows Explorer and Open in Oxygen should open the file in the running instance of Oxygen. If a second instance is started on your computer either you added the Oxygen startup parameter -Dcom.oxygenxml.MultipleInstances=true or there is a firewall or antivirus application that blocks the connections to local ports (by default the second instance tries to connect to a local port to see if there is a first running instance). In the second case you should add Oxygen to the list of exceptions (applications that are allowed to connect to a local port) or disable this blocking feature of the firewall. Regards, Sorin Robert Nagle wrote:

In Windows vista 64 , when I right click an xml/xsl file, a new and separate instance of Oxygen will open up. Is there any easy way to instruct Oxygen to open the file in the previously opened Oyxgen instance rather than to open up a new instance each time?