Don't waste your time trying to fix the CD drive. 99% of the time, nothing can be done.
Pull the drive out, put in a new one, and call it a day.
There is nothing to be worried about when changing a CD-ROM drive. Unscrew the old one, remove it, change the jumper setting on the new one to match the old one (eliminates any configuration), install the new one, done!
BTW, using a cable modem via USB interface is complete garbage. I find computers having issues with disconnects, slow response, etc. all the time using USB. Using USB simulates a ethernet card in Windows. So your modem is now performing 2 functions.
Do yourself a huge favor and get a ethernet card if you do not have one already, and connect the modem through ethernet. It is a much more reliable and stable connection. After all, that is what it is made for. Leave USB for keyboards, mice, cameras, scanners, printers, etc.
