Windows XP - Log in problem

Few of my friends cannot log in to my weblog because they are using Windows XP. I heard that you can download a console somewhere at sun microsystems. But what is the best solution to fix this problem. When visitors cannot log in they cannot give comments. Is there a way to make internet explorer download a special plugin so people can give contributions.

When you open a flash animation for the fist time, internet explorer goes looking for a flash player plug in. Is there a option to install it on antville, so when people have no java installed, it will look for a plugin to install, so they can log in and give comments.