While this error can indeed mean anything, like faulty hardware - it is indeed VERY OFTEN related to bad, cheap IDE/Sata Cables. I had this error multiple times already and i just again finished exchanging SATA cables on a PC to fix the errors.
Main sources of the Event 11 Atapi error are
*) Cheap SATA cables, usually those which come with your motherboard
*) Old SATA cables which are used in a PC for some years already
*) Low quality SATA cables
The error can appear "all of a sudden" after months or years - and there is no visible indication that something is wrong, all cable connections look fine. The problem is that SATA cables and connectors have a very low life-span, unplugging and re-plugging
them a few times could already be reason enough to replace the cables.
( The error can cause lock-ups and delays in working with your PC since the PC tries to access drives and encounters errors, or your PC/Windows can also switch your IDE/SATA controller from DMA mode to the slower PIO mode which means that your drives will
work less efficient than using DMA mode! Also..the indication that there is an error on "Atapi" does not necessarily mean that the connection to your CD/DVD drive is affected. I just did some troubleshooting assuming the same thing - just to find out it was
actually the SATA connection on my second hard drive. )
Solution: Get high quality SATA cables with metal latches. Replace ALL and ANY of the Sata cables, especially if you use those which came with your motherboard. I had this error multiple times already on various computers affecting various
drives, burners and hard drives. Each and any time replacing the cables fixed the problem.
Georg.