Transferring software to new computer?

I am getting a new tower delivered to me soon so I decided to get all my "ducks in a row" first. I want to transfer my software programs with no problems to the new computer. I bought WebRoot "Window Washer" in 2006 and I have the physical disk and registration#. I recieve software updates from them and am running the current version. My perdicament is, that I contacted them to get my acct. Info., and they don't seem to know me. They want me to buy the product again. Do I just forget them and reload the disk with the registration #. They must be in the UK because they are rather snooty!