Bundled software not part of the order.?

My pc manufactuer/seller has told me that because a program which they sent me as bundled ( already downoaded on to the pc when I bought it new ) was not on a disk it was therefore regarded as not replaceable by them for free under the guarantee. They refuse to send me a re-placemant disk unless I am prepared to pay for it, even though everything is still under guarantee. ( It seems the program is not available, by now at least, as a free download from Microsoft, it's originators.) Can you please tell me if they are right to take this attitude? (Incidentally the program was causing me problems with Outlook Express, which is why I uninstalled it. Following other changes to my settings I'd now like to know if the problem will recur if I reinstal it. I suspect it would not cause me problems in future, but I don't want to pay for it if, obviously, in case it does.)