Don't waste your time cliff. Although there are many different 5000 series all are ancient. I had one myself.
Besides the outdated unsupported operating system there is not one piece of hardware worth upgrading. You would need a new processor, more RAM, bigger hard drive and a new operating system to start with. For a fraction of the cost you could buy a new unit that is many times better even after upgrading.
You would have a hard time finding software that runs on ME anymore including an antivirus program.