If your manually installing donwload the updated version to your desktop.  After this is complete remove all the old versions, then double click the donwloaded Java icon that is on your desktop to install.

 

You are correct.  There is no reason to keep the out dated version.   

I went to java.com and clicked on the free java link. I was asked to install an active X control and then I installed the newest version of java. I only need one version of java which would be the most recent one and I would just toss the old one. I wanted to make sure that my knowledge was correct.

If you leave the older versions hanging around it is bad because it may be possible for an attacker to exploit known bugs in the older versions.

I already got rid of the older version that I had.