I'm Sorry Mark, did'nt wanted to sound rude (my english is still too crude), Neither as an expert on the topic. I was trying to say that a complete backup or emergency measures were not necessary according to the symptoms.
All media, without exception, has impurities, even brand new. Fortunetly, the HD includes an algorithm to ignore that sectors and mark them as unusable, and write elsewhere. The process is transparent, even the OS didn't know when that happens.
When the HD fails or start to fail, chunks of data dissapear, you can't find your files, and nasty blue screens of death appear. As you said. Strange sounds are also the cherry on the cake.
Now, consider the unstable and corruptable Internet Explorer, or Java (I mean, Java is great, I'm talking about the nasty message of "files are in use", "read only", stuff like that). As far as the OP said, only java was affected, not the personal files or whatever, so I discarded a HD failure at short therm, and diagnosed a inocuous software problem.
By the way, DVD's are cheap, so a backup is not a bad idea, even for healthy computers