The PCI read error is pretty funny, since there's no PCI anywhere on that PC.
A TV tuner card lets you watch TV on your PC. Either attaches to a cable, or an antenna, I suppose. I've never had one myself.
(I'll get to the install issue in minute)
You'll have to open the box to see if there's an open ISA slot. I had to go look at an old VESA Local Bus mobo here at work to refresh my memory as to their layout. The VESA Local Bus slots are just gigantic...they go all the way across the motherboard. The ISA slots are not quite as long, and are usually next to the 72pin SIMM memory slots (the ISA slots on a VESA board are where the PCI slots are on a PCI board).
Hope you got an ISA nic (don't spend more than $5 on this box, someone is bound to have an old ISA nic somewhere for you for free....they also might have a pair of old SIMMS you could try: they install in pairs)
While you have the box open, jot down the make/model of the Cd-rom and sound card and we'll see if we can find a driver to put on the boot disk. (the Compaq site might have something)
If we can get the right driver onto the boot disk Dr Zaius had you make, then you should be able to install as he instructed. Maybe. It's just for fun anyway: we may find, as Texas2Step mentions, that it won't upgrade to Win95/98 without serious magic.
I'll check back after dinner
. . . Gary