If you have a USB port on your old WinXp machine you could try out what your missing by installing Ubuntu Studio to a USB stick and boot off that into a temporary live setup. I tried it, and it works, and was quite easy to do.
!: Download Ubuntu Studio and "Rufus" USB installer app.
2: Rummage around in your drawer and find any old USB stick and use Rufus to install Ubuntu Studio.
3: Download Nils K1v Linux version and put it somewhere easy to find.
4: Boot into Ubuntu Studio and install Wine from a terminal - sudo apt-get install wine -
5: Click on Nils VST and install
6: Download the Bitwig demo and install and generally setup in the settings for your machine.
7: Run "Carla" which is pre-installed in Bitwig and press "add" in Carla and find and add the VST.
8: Play