Best Virtual machine software to try W10 TP on Windows 8.1

Can anyone recommend the least heavy (change in system prefs) and size, virtual machine software to test W10 TP on a Windows 8.1 Pro x86 desktop. I have tried VMWare Workstation in the past but find it is no longer free, I would like to have a quick look at W10.

Thanks in advance

Tim

You can still make use of VmWare Player for non-commercial use for free.

Many thanks Buns

And here's a tutorial by Brink - works the same for installing Win 10.
VMware Player - Install Windows 8

I prefer Windows' own native Hyper-V, to set it up in your Windows 8.1 Pro and install Windows 10 Tech Preview, simply follow the instructions in this tutorial: Hyper-V virtualization - Setup and Use in Windows 10

Although tutorial is written to Windows 10, the Hyper-V in Windows 8 Pro & 8.1 Pro works and functions exactly the same way.

I cant get hyper v to run on my desktop as it says the hardware is too old memory wise

Is VMWare better than VirtualBox at running as 'full' a full-screen mode as possible?

For me VMware Player full screen works just like my Host OS in "full screen".
I don't use VirtualBox so I can't comment on any difference with that.

I normally use the VM in "Windowed Maximized" so I can see both OSs at the same time.
Some W10 modern apps don't work right unless the VM is "Full Screen".

I prefer Windows' own native Hyper-V, to set it up in your Windows 8.1 Pro and install Windows 10 Tech Preview, simply follow the instructions in this tutorial: Hyper-V virtualization - Setup and Use in Windows 10

Although tutorial is written to Windows 10, the Hyper-V in Windows 8 Pro & 8.1 Pro works and functions exactly the same way.

The OP asked for the LEAST HEAVY VM software which would automatically exclude Hyper-V which requires Win 8.x PRO and 64-bit making it the most demanding VM software I have ever encountered.

First, Hyper-V uses less host resources than for instance VMware Player.

Second, who on earth would like to do some serious virtualization in a system with less than 4 GB of RAM? If you have 4 GB or more it's quite natural to assume you have an x64 version of Windows.