Can't help with your installation problem but, once you get the ScanSoft software installed, be aware that we've found that the 'opware32.exe' process can have a few side-effects, e.g. previously installed applications hanging/crashing.
If you experience this, try closing the 'opware32.exe' process to see if it is the cause. If it is then the process can be disabled using MSCONFIG. This doesn't stop the ScanSoft programs from running.