Is there a way to restart without shutting down first on Windows? On Linux this is possible using kexec and serves to minimize downtime. What happens is that one does not pass through the bootloader stage and no BIOS is seen.
I do not believe it is possible. As Moab pointed out in the comments, it used to be possible in Windows 9x.
That used to work by unloading Windows, going to the DOS environment, and reloading Windows again (if I recall correctly, one could simply type in
Disclosure: I wrote ShutOff 2000, so I've been fiddling around with ways to shut down Windows since 1999. I don't claim to know all there is about it, though.