If the file you have in your system directory is version 6.1.9844.0 then that is the most current version. You can replace it but beware that it may cause more problems if a different version is there. Plus, if you remove it, Windows might just replace it again with it's own version. That said, you can use Killbox to delete the file on bootup:http://www.bleepingcomputer.com/files/killbox.php
I don't recommend doing this but it's up to you.
As for your question regarding registry cleaners, I wouldn't pay for any of them. There are many good free ones available and it has been my experience that the commercial versions give you many false positives to get you to buy their products. I have tried many free ones and the one I like the best is CCleaner. Here's a link:http://www.ccleaner.com/
I will run this after I uninstall any major softwrae package and then routinely every couple of months. Have never had any problems.
Sorry I didn't have any furhter information regarding your Nero problem.