A few months ago, my PC was absolutely inundated with viruses. It got to the point that I had to reformat everything, and pull all my backups off an external harddrive.
Months later, it occurred to me that there might be viruses on that external HDD. I don't know for certain, on account of that whole period being a very chaotic time, but there is a chance.
I saw that there is a sticky post about using a couple software tools to prevent USB flash drives from autorunning things once they're plugged in. My question is do I need to take any special precautions like that, or can I just plug the external HDD in and scan it straight away?
If it has an autorun.inf file that runs a nasty, and your PC will run autorun.inf files automatically, then yes, you could get infected. IMO, I'd run the Panda Immunization app and and make sure the PC is vaccinated (see my photo.) Then, even if the external drive has a virus that wants to autorun, it can't.