To expand on what Peerless said, yes you do need to clean your computer dvd/cd player now & again (just as a normal cd player, if not more-so because of computer cooler fans causing a vaccum sucking dusty air through the computer). Otherwise reading slows down, it can get to the point where it does not or has major problems to recognise some or all disks.

Some burners work best with particular brands (much more reliable). And some only work with certain brands. Same applies with set-top dvd players (but some, sometimes the cheapest set-top dvd players are not fussy at all.)

There is a web site around where you can check (if they tested your model) for the pluses & minuses of certain models ... which brand disks work best with them, which don't work at all with them, etc. Mindblock! I will find the url address if you wish.

Thank you both for your help. I bought Verbatim DVD+R disks. I believe my computer has DVD-R.

How should I clean my disk drives? Is there a disk that I should buy?