How do I find the software needed to download music from computer?

Hi Alberta...go to www.google.com. Type in ''s0ftware f0r (the model of your mp3 player) and press search. A wide range will be displayed to you. Choose the one that suits you best and follow the instructions to download your software.

Depending on the brand some come with software. Sandisk Sansa fuze for example has a disk but you can use windows media player or just use the old drag and dropprocess. MachSpeed Eclipse has software on the device that you need to transfer to you pc/laptop.
A lot are usable with windows media player some require (not necessary though) other software to convert then transfer music. As for videos I have not found a viable stand-alone converter that works well. Even some provided software is total junk such as media player player utilities 5.22 which is part of the software included on Elcipse. The A/V sync and there is no software update (software is no longer around). Media monkey will allow for usage to sync between various devices/mp3 players as well as musik cube (no longer around but can get download from downloads.com)
Sandisk Sansa and Eclipse are the only 2 I have personally bought and know about pertaining to software but most can use Windows media player to transfer. Or as I said drag and drop. Just open you music folder open my computer/computer Find your unit and just select the music drag it over and drop. If that does not work may have to open your device in my computer and place your music in the music folder on it.