Well, it does seem you have other issues going on. Since, I'm not there you have to describe as best as possible. You mentioned, "malware" well any form of that isn't going to be good. If that was already a problem prior to anything you stated before, that could be a reason for not being able to boot the CD, maybe. If now its a problem, because you got new s/w and "you" let in, then you have complicated issues and/or all the more to clear out. If you can't update your protection schemes so they have the latest defense and run anyways, it may not report finding anything because it doesn't know about the latest threats. All in all, it gets difficult. CAN you at least burn the s/w on another PC, a friend's or school, etc.?
FYI- I don't install *any* browser toolbars, any! It becomes too easy for issue/problems to arise, so I decline them. Even, if you don't use a browser at any given time, allowing the toolbars may have allowed other unwanted or pests to enter your system. Even if not nasty, they hog resources, etc., they become a load which at times makes operations take longer or appear to hang/freeze. So "Ask Jeeves" , i would decline, and there better be an "uncheck box" in order to continue the install. If not, STOP and delete that pgm. I wouldn't trust it. So, its important to trust sources of pgms or apps to install. I suggest you check out these websites:
Even, if any of the above seem to give notice of problems, STOP and exit and delete that recent gotten pgm.. Notice, I didn't mention CNET downloads, I find it with all the problems you have now, just get from another source. Alas, you needn't open the .ISO file, you direct your burning s/w to it and select it and then burn, which IMGBURN does quite well. BTW, I re-read your 1st post, WHY is the dead CD drive still attached, remove or disconnect entirely. make sure the DVD drive is 1st on cable or primary drive. That may cause a slow response to burn. On top of all this, you never supplied details of your PC brand or type. 10yr. PC, it is very probable that the PC doesn't allow USB boot-up, but for now I can'rt asset that.