Go into device manager (Windows key + R, type devmgmt.msc, press enter) and go to IDE ATA/ATAPI Controllers. Double click each of the ATA Channels, go to Advanced Settings, and make sure "Enable DMA" is checked at the bottom for every single one. If DMA isn't on for one of them, right click -> uninstall it and restart your computer. Windows will reinstall it.
Otherwise, you may have some UpperFilters/LowerFilters in the registry that are affecting performance (not all of them affect performance). Or it could be Daemon tools, which installs sptd.sys that can make your burners work slowly (see here: http://forum.imgburn.com/index.php?showtopic=14396
If you have daemon tools installed, uninstalling it won't remove sptd.sys, you'll have to download this: http://www.duplexsecure.com/download...t-v175-x64.exe
from here: http://www.duplexsecure.com/en/downloads
(the company that makes daemon tools) and use their installer to remove sptd.sys
Best of luck.