Hi All - I am having problems getting the "Allow only one instance of application for each user" option to work in our Citrix farm. Presentation Server 4 - running latest patch levels - Win2k3 with latest patch levels. The problem seems limited to published apps which run a batch file (the batch file generally loads some config, launches an exe and then exits). There are no errors/logs - it simply allows multiple instances of the published app to be launched. I have tried this with and without session sharing enabled - same problem. I am presuming it is because Presentation server cannot find an instance of the batch file in memory that the apps is configured to run, when the second connection is launched, but don't fully understand how it works. Any help appreciated. Cheers, Shane Rees Senior Systems Engineer Server Management - Network & Infrastructure Support Mincom Managed Services Level 6, 193 Turbot Street, Brisbane, QLD 4000, Australia Phone +61 (0) 7 3364 9876 Fax +61 (0) 7 3364 9777 http://www.mincom.com Mincom. The People. The Experience. The Vision. This transmission is for the intended addressee only and is confidential information. If you have received this transmission in error, please delete it and notify the sender. The contents of this e-mail are the opinion of the writer only and are not endorsed by the Mincom Group of companies unless expressly stated otherwise.