Creating a bootable usb for MacOS from Windows 10 I've a MacBook Pro and recently my hard drive kicked the bucket. I bought a new ssd drive and installed it in my MacBook.

Now I have to create a bootable usb to install latest MacOS. I've spare a windows pc. Researching, I found that I could use Transmac software to create one.

However, the official ".dmg" file of latest macos (i.e., high sierra) can't be downloaded from PC.

Is there a way to download this file from a PC?
In a word, no. 

I am sure there are "unofficial" downloads but do you trust that? Me neither. 

Put the model of your Mac in your question, as that matters. 

Most modern Macs have Internet Recovery. Reboot your Mac holding COMMAND R. Which will get you into Internet Recovery mode, allowing you to connect to a network and download the version of the OS your Mac shipped with. Once that installs and boots properly you can download a later version if you like.