Computer failure #2

So, I decided to re-install Ubuntu since it has been running a little too slow and I wanted to re-size my partitions while I was at it. I insert the CD, restart my computer, change the booting order to CD first and... it doesn't read it, I boot windows to see if the disk was ok (it doesn't look like is damaged), and it does not read it, after some tries I decide to use another CD and it doesn't read it either, I tried with some audio CDs and movie DVDs and nothing.

I haven't used my CD-ROM for quite a wile, I only used it to install Windows or Linux, but nothing more, well, no problem, I only had to learn how to boot from a USB flash drive, which I already wanted to do, it is more reliable and economic than using CDs/DVDs.

And since I'm already doing this i'll do it with Windows too to see how fast it is :P
After this I was thinking of buying an external DVD burner, but since I almost never used it I see no purpose in buying one.