When windows installs drivers such as the .sys files that you mention, these are located by via the windows drivers database that it builds from the .inf files that 'point' to the actual drivers.
.inf files are, effectively, installation instructions telling Windows the details of the driver files, where to find them and where / how to install them.
You could try the following:
Locate the relevant .inf file on your system and remove this. So I would suggest searching for .inf files that refer to the .sys files that you mention (you may be able to determine what the .iinf file is called by looking on the CD that you mention).
Having removed the .inf file, then make sure that the drivers are uninstalled and reboot. Windows will then not find the .inf file and should then revert to doing whatever it was doing beforehand.