COM Plugin

I think the correct progID for explorer is "InternetExplorer.Application", I just tried here in Win 7 64-bit and it works fine.
Please try with the correct progID and let me know it it works.

Also note that you can only run 64-bit DLLs on 64-bit Java, if you want to run 32-bit DLLs you need to launch Servoy with a 32-bit JVM.

To know what version of Java you have installed you can issue:
java -version
on the command line.

This will output something like this (where the version is the one you have):

java version "1.6.0_27" 
Java(TM) SE Runtime Environment (build 1.6.0_27-b07)
Java HotSpot(TM) 64-Bit Server VM (build 20.2-b06, mixed mode)

As you see the 3rd line states that this is 64-bit JVM

Otherwise, you will have something like this:

java version "1.6.0_29" 
Java(TM) SE Runtime Environment (build 1.6.0_29-b11)
Java HotSpot(TM) Client VM (build 20.4-b02, mixed mode, sharing)

In Developer, you can also open the "About Servoy..." menu, click on the "Installation Details" button, go to the last tab "Configuration" and look for the line just below -arch it will states your architecture, which on Windows, will be x86 or x86_64

In Developer's Debug client, you can choose the "Help > About..." menu and the same Java version will be on the 3rd line again.

On a real Smart client (launched from a jnlp URL), show the Java console (you can activate that in your Java preferences panel), the first lines will be the version used by the client.

Now understand that if you use Java 32-bit, you can only use 32-bit binaries, so 32-bit COM components.
If you use Java 64-bit, you can only use 64-bit binaries.
This is a Java limitation, not a COM plugin limitation.

Depending on the components, some exists in 32 and 64-bit version, like Internet Explorer for example, so you dont need to change a thing to use it, whatever the Java version you use.

Some don't have both DLL available, and you're out of luck because in that case: you will have to ask your clients to install a 32-bit JVM (which works fine on a 64-bit OS) to use your app, or use COM on the server side with a Java version installed on the server that matches the architecture of your COM component...
This last option will also require that you write special wrappers to communicate with the server-side COM component though, which can be done in a plugin - like the Firefox plugin I'm working on, and in that case also, you will not be able use COM components with a UI.

Hope this clarifies.