I want to change the directory location where temporary internet files are stored. I am running version 3.5.
See this KB article:
Your above posted system details show outdated plugin(s) with known security and stability risks.
Update the Java plugin to the latest version.
Update the Flash plugin to the latest version.
You can also update to Firefox 3.5.13 via "Help > Check for Updates" or to Firefox 3.6.10