Don’t tip a computer that has a CD spinning in the drive. The resulting gyroscopic perturbations will do bad things to the CD in the drive.
I was re-installing XP on a newish Dell 2400. The XP product activation code is written on the side of the PC. So when I needed the code, (the computer was sitting on the floor and I was in a chair) I tilted the case. The resulting noise sounded like a circular saw that was trying to cut through a piece of wood that was just too thick. Once the CD came to it’s (literally) grinding halt, I took it out and found a long circular gash in the disc.
So I’ve spent an hour with a Skip Doctor, trying to read the disc. No luck yet but I think I’ll get it eventually. Feh!