Ahh, this is how I have to play. My nice shiny laptop died and now I'm temporarily back on a resurrected PIII desktop with a cdrom drive from like the 1970's (ok, more like 1995 but sometimes I wonder)
This old pc's cdrom drive can't recognize the diablo play disc, probably because of the copy protection, which uses some Advanced Features (TM) of cdroms that I won't name. This is fine with me, because I'm a hungry programmer myself, and when I develop carpal tunnel syndrome to get a product out I expect people to pay for it. But in this case, if I try to insert the disc, it just gets spit right out again. The drive is so old it simply can't handle it.
So what I had to do to play my personally-purchased and entirely legit diablo 2 is this:
1. Load the cd into a cdrom drive that can actually read the disc. This will likely be something manufactured after the Reagan era. It will also likely be on someone else's computer, because using the cd itself is faster, and you have to be really lazy to slow down level loading by a factor of 10+ just to not have to insert a friggin cd.
2. Use some software that I'm not going to name here, that allows you to create a cd image file of the disc onto this other PC's hard drive, including the necessary extra stuff that your old cdrom drive can't read. Doing this can raise some hairy legal matters, and I'll just leave it at that. This is not a very good explanation, but it's intentional, and I'm not going to be more specific about it.
3. Get daemon tools, which you will have to find yourself at your own risk and possible prosecution, but which will allow you to mount this cd image as if it were a real cd inserted into a much more modern cdrom drive. You may also install viruses, trojans, and backdoor exploits onto your system along with this software, about which warnings are all over the place, and you are really using this hazardous software at your own risk, etc. No kidding.
4. Mount the image with daemon tools. Diablo should accept this as an actual CD and act accordingly. For me, I was able to install and run diablo with my physical cdrom drive, except for the recognition of the play disc, so I used my real cdrom drive for all the other discs, and keep the play disc mounted with daemon tools. Did I mention that many people who use daemon tools also find their systems infested by nasty trojans and viruses? Proceed with caution.