If you use M$ then look at using 'md5sum.exe
If you downloaded the cd/dvd iso then be sure to check the md5sum for the original iso. From the cli on GNU/Linux;
~#cd /downloadisolocation #cdromiso.iso cdromiso.md5
~#md5sum -c cdromiso.md5 #substitute the correct name to check
If the iso md5 is ok then you should try 'CdromMd5sumsAfterBurning'
This way you will know if the burn was OK!
This will check the download iso with the known md5sum that you also get with the iso as a text file that contains the signature.
The above links and others available from 'Slackware-Links
'. More than just SlackwareŽ links!