1. the question is: is it safe for or against what?
2. there is no absolute 100% safety: security is a process, not a product/software/app!
3. if your host-system is compromised or unsafe (which i would consider default windows 10 to be), your guest must also be considered as unsafe/compromised.
4. running a live-system - from an unwritable media (CD/DVD) - is even more secure than using an installed system, whether in a virtual machine or not: eventual malware is easily gone after a reboot and so is also every additional software/data to possibly track you.
5. i don't expand on hardware related issues to keep it somehow easily understandable, but your hardware can also be compromised, which makes it nearly irrelevant which software (programms and OS) you are running.

TL;DR:
for maximum safety with not that much more effort (WARNING: trade-off), i would advise to

1. use Tails directly on your machine from a liveDVD and update it immediately.
2. change as less as possible in the live session (only if you really, really know what you are doing and completely understand its consequences).
3. follow the Tor rules: Want Tor to really work?
4. read and understand the Tails warnings: https://tails.boum.org/doc/about/warning/index.en.html

1. the question is: is it safe for or against what?
2. there is no absolute 100% safety: security is a process, not a product/software/app!
3. if your host-system is compromised or unsafe (which i would consider default windows 10 to be), your guest must also be considered as unsafe/compromised.
4. running a live-system - from an unwritable media (CD/DVD) - is even more secure than using an installed system, whether in a virtual machine or not: eventual (not hardware-related) malware is easily gone after a reboot and so is also every additional software/data to possibly track you.
5. i don't expand on hardware related issues to keep it somehow easily understandable, but your hardware can also be compromised, which makes it nearly irrelevant which software (programms and OS) you are running.

TL;DR:
for maximum safety with not that much more effort (WARNING: trade-off), i would advise to

1. use Tails directly on your machine from a liveDVD and update it immediately.
2. change as less as possible in the live session (only if you really, really know what you are doing and completely understand its consequences).
3. follow the Tor rules: Want Tor to really work?
4. read and understand the Tails warnings: https://tails.boum.org/doc/about/warning/index.en.html