Someone at another forum suggested I edit registry entry to change the default path from that invalid path. I did, and it worked.

HKEY_LOCAL_MACHINE\SOFTWARE\Node.js

@PitaJ Sorry, but that doesn't work at all.

After some thought, I created a new restore point and tried a completely new clean installation.

I downloaded the installer anew from the NodeJS site, but on trying to run it, I got the same message:
Invalid drive: O:\ (that's the drive that is gone - no longer accessible or even now connected). And, the installation process immediately quits.

Won't all the registry entries from the prior installation in that now unavailable drive interfere in any way? Will the new installation then work with all my previous projects that used nodejs? I'm a little uncomfortable with jumping right in to do a new installation when there are traces of an old one.

I'm using a Windows 10 Pro PC and the drive on which I had installed NodeJs became inaccessible. I've sent it away for data recovery.

Meanwhile I tried to repair the installation. I was asked for the msi, which I did save on another working drive. However, that still looks for the inaccessible drive.

I can't change or uninstall it because the processes still look for that invalid drive. Can I try to re-install it on a new valid drive, or will that possibly mess everything up?