After trying out ImgBurn which is recommended by @Tech Support Staff 1 and @Tech Support Staff 2, I got this Duplex STPD warning message on imgburn. following some research, people said that it's part of Daemon Tools Lite which I have and probably made the burning process slower than normal (which I'm experiencing right now, writing speed is varying a lot below 1.0 x speed according to imgburn). Alcohol 120 apparently has it too. so, any suggestions for things other than Daemon/Alcohol which does not have this Duplex STPD stuff? mainly for mounting disc image files purposes. from more reading, some people suggested Virtual Clone Drive but I want to know if there are better programs, so here I am asking you IT guys for your insights.