The information in this article applies to:
How does the Msdev.exe in Visual J++ relax the security in Microsoft® Internet Explorer so that my applet can run outside the Java sandbox, despite the fact that it is not in a signed .cab file?
In the Microsoft® virtual machine (Microsoft VM), which is included with Internet Explorer 3.x and 4.0x, only trusted class files can access resources outside the Java sandbox. Class files from digitally signed .cab files are trusted. If the HTML file is run from Microsoft® Developer Studio®, the class files are also trusted. This can be very helpful during applet development. However, to deliver your applet to other users, you must place them in a signed .cab file.
When executing or debugging a Java applet from Developer Studio, the security restrictions in Internet Explorer are relaxed for quick and easy testing. MSDEV prepends the project path to the CLASSPATH that is used by Internet Explorer. This gives the classes trusted status.
Applets outside of MSDEV must be cabbed and signed in order to run in Internet Explorer without the sandbox restrictions. One of the references below is a FAQ about cabbing and signing.
Note All trusted applets (including those running under Developer Studio) running under the Microsoft VM (version 2252 or higher) included with either the SDK 2.0x for Java or Internet Explorer 4.0x have additional restrictions (please see references below).
For additional information on making your Java code trusted in Microsoft Internet Explorer, please refer to the following Knowledge Base article:
Q193877 HOWTO: Making your Java Code Trusted in Internet Explorer
For more information on .cab signing, please see the SDK for Java documentation and the following article in the Microsoft Knowledge Base:
Q168941 INFO: Frequently Asked Questions for .cab Files
For more information on additional security restrictions for the Microsoft VM (version 2252 or higher) included with either the SDK for Java or Internet Explorer 4.0x, please see the following article in the Microsoft Knowledge Base:
Q175622 PRB: SecurityExceptionEx Exception Running a Java Applet
For the latest Knowledge Base articles and other support information on Visual J++ and the SDK for Java, please see the following pages on the Microsoft Technical Support site:
http://support.microsoft.com/support/visualj/
http://support.microsoft.com/support/java/