wow man you really got forgeted over.
hey also i noticed
nobody brought up this:
System Restore
then again I may be wrong considering your zero access rootkit royally forgeted an important Windows sys file and could not be deleted or changed.
so yes your best option at that point would've been to completely re-format your HDD.
which I see you've done obviously.
be more careful next time.
and it doesn't matter what sites you visited or what you downloaded in the past 24 hours.
it is still completely normal and 100% possible to just get handed a virus without you even knowing it, especially if you're lazy with firewall settings (meaning you let any program on your computer firewall access regardless of what it is), your antivirus (or have a very bad one), and your home network (if it's not secure).
hell you could've easily downloaded a dormant virus months ago or even a year ago and it slept for a set amount of time and then bit you in the ass. those do exist.
that is the meaning of a trojan virus after all.
to sneak into your system any way possible without you even noticing.