I'm running Windows 8.1 64 bit, it's a HP Envy Recline with Beats Audio. I bought it new as I was having the same issues as you with an old laptop. I still have the laptop as a backup but haven't used it for about 9 months. So, everything below is freshly installed. Some of them with a few minor challenges needing compatibility mode.
Sd Jukebox 2.4 installs and works perfectly. In fact it is the program with the least issues, very straightforward. Yes, it will enable the transfer of mp3s as you describe.
Song Manager installs and functions but won't transfer anything via USB.
KN7000 drivers install and work fine, using compatibility mode (there's an article on my UK website about this).
Jukebox 5 has never worked for me.
Techmanager is up and running in compatibility mode (works fine) but I found it challenging to install (I had to find various files around the Internet that weren't on Win 8.1).
KN-SDExplorer demo and full version work fine, with a few workarounds that I've explained on the KN-SDExplorer website. And we'll be releasing a new version in the near future we are near completion on testing.
EMC Styleworks Technics and EMC Styleworks Universal have been updated several times recently, they work great on Win 8.1 64 bit.
SD Origins download on my website is the quickest way to initiate an SD Card on Mac or PC, contains 727 Styles and sets up your directories for importing MIDIs etc. My son has a Mac and we've thoroughly tested it.
Technics KN recorder software works fine for recording from USB.
I recommend getting a good MIDI interface rather than using the USB, it works better for me (for MIDI). I use the USB for recording. Windows 8.1 also recognises the KN7000 as a speaker system.
Some of the above might depend on the processor in your PC and mine is 64 bit so I can't confirm for 32 bit but I understand that 32 bit is usually less problematic.
I haven't failed to get any of the other various Technics keyboard programs running but there are sometimes quirks such as the help file won't load.
I've written at length on most of these subjects on my websites, can't repeat it all here as there is so much but I hope that helps you.
Edited by designserve (04/01/15 05:46 PM)