Test C# OS. Latest download link. Please use VMware as a virtual machine. I do not recommend you to run this OS on real hardware as it may cause your PC to break down
You will need to create a drive because the OS needs to have a filesystem available to write and boot.
First of all, you need a second virtual machine with either Windows or Linux installed (I have Arch and show commands for it)
Add an IDE hard drive (edit VM -> Add -> Hard Disk -> IDE -> Define a size you desire and set "Store virtual disk as a single file")
In your virtual machine format the drive as FAT32 (for Linux use the command mkfs.fat -F32 /dev/sda and replace sda with your drive identifier)
If you want you can mount the disk and place some files/packages inside
Next, in the VM where you want to run WinttOS, add a drive (except, instead of 'Create a new virtual disk' select 'Use an existing virtual disk' and select the drive you've formatted)
After that select your hard drive, then click Advanced, and make sure that the Virtual device node is set to IDE 0:0 and CD/DVD set to IDE 1:0
Now you should be able to start WinttOS