When I was young, the PC tutorial stuff I saw was a bit more boring than you describe - particularly since we had Hercules graphics which is monochrome - but I was interested to look, because I remembered software we had called "PC Professor" which I thought might be similar. I think that might have just been for learning BASIC though.
I found some candidates by looking at the PC-SIG Library on CD-ROM 13th Edition. This is a collection of shareware software with a well-written catalog. In case you want to look yourself, I started the hypertext reader (it's a graphical DOS program), then went to Categories -> Education -> DOS and PC Training.
Here's what I found, with links to view some of them on pcjs.org:
Tutor by Association
This might be what one of you remembers, but I didn't see anything about CPU, RAM etc. diagrams in it. It looks like I would have enjoyed it when I was a kid though!
To try this one out:
1. Go to pcjs.org and start a machine with PC-SIG disk #3915
2. Once it's finished booting and shown a directory listing of B:, run B:GO
3. Press a key
4. F2 ... Install
5. F1 ... Tutor
6. Enter to accept the directory
7. Once it's done, run GO
You might want to click the button that says 4.77MHz at the bottom right corner of the screen a few times to speed it up.
TUTOR DOS
1. Go to the pcjs.org PC-SIG page without any particular disk loaded
2. In the search box a little way down the page, enter "2384"
3. Click the first result ("DISK2384")
4. Run B: then GO to see instructions
5. Run INSTALL B C
6. When prompted for disk 2, select the link from the search results
It never prompts for disks 3 and 4, I guess because it thinks you hit the key more than once. You can see most of the lessons anyway though. I imagine you might be able to work around this by re-running install from disks 3 and 4.
7. Run C: then TUTORDOS
This one doesn't seem as fun as the first one!
Others
This one, which is also available at the above pcjs.org page, is older and more boring: DISK0403 - COMPUTER TUTORIAL
The pcjs.org page is missing another one, PC-SIG disk #1399 PC-LEARN. I looked at the version from the PC-SIG 9th edition CD-ROM. It's completely black and white, and you're just paging through text files, so it must not be what you're after.
