If you are using Win98SE or earlier look on the Microsoft.com web-site under their 'knowledge base' for JVM - Java Virtual machine. It's a seperate set of files that forms part of your operating system and can be reinstalled back on top of the operating system. Microsoft used to list the files/program required along with the instructions on how to do it. If the JVM corrupts, you will get java errors.
Richard, October 2004