Computer dependence

My PC has crashed--apparently from a combination of a nasty virus and too much dust.
Our friend Vince came by to see if he could start it again after it went into a loop that couldn't quite open Windows, and showed me the dust problem. Apparently the magnetism involved in computer operation attracts dust particles in even the most spotless houses (which mine isn't), and when it builds up to a certain point the fans overheat and fry something--in this case I think the hard drive, and the motherboard succumbed to the virus, but maybe that's backwards. However, the point is that we should all have a nice big can of air next to our computers and open them up and use it to blow the dust out of the fans fairly often.

At any rate, I'm using my beloved Thinkpad, bought for our Europe trip last year, and realizing how much of my life and work is on these machines.
Among other things, all the photos for my stores and of my family are stored on the PC, meaning that I can't post new items without re-taking pics UNLESS I can pull them off my external hard drive, on which I back everything up frequently. I'm about ready to have a run at that--I think most of the photos (except maybe the most recent ones of our newest granddaughter) should be there, but I've never tried to access them. I used to back up on CDs, which took a long time, so when Seth got a newer bigger drive & gave me this one, I was delighted: it can back up not only quickly, but while I'm doing something else. The only question is, can I read it?

I am reasonably computer savvy--at least I know when I've reached the limit of what I can do and need to call for help--but I'm still intimidated about trying new stuff without guidance. I'm pretty sure that attaching the drive to this machine's USB port is safe, and that probably I can access it--but then what? Is it formatted like my computer? Can I just go to the pics? Or will I have to wade through oceans of code trying to find something I recognize?

Well, the PC is over at Vince's undergoing whatever lifesaving procedures are available, so I'll just have to take a deep breath and give it a try.

For anyone else whose relationship to this stuff is similar, I'll report back.