error codes meanings

I have an inspiron 1520 laptop. A couple weeks ago while I was playing a game on my computer my system went to bluescreen and told me that i had a hardware malfunction. I restarted and it worked fine. A few days later while playing the smae game it happened again. I restarted again and there were no issues anywhere else. The third time it happened I decided to run a diagnostic on my system. I got two error code messages. The first was 2000-0142 drive self test faild status byte = 79. It came on a hard drive test I believe. The other message was 0F00:021C Block 826 non recoverable hardware error (timeout on logical unit). This same message repeated for 10 more blocks before I stopped the test because I didn't want to check all 163280 blocks with it failing every 10 blocks or so. These messages were on an optical disk drive test. I was wondering if someone could tell me what these messages mean and what I should do about them.