Difficulty installing software with Dragon Naturally Speaking Preferred 10 Software

I used Dragon Naturally Speaking Preferred 10 Software for installing some program.
During the installation, I entered the product license as necessary.
However, a window Popup keeps asking for windows username and password. Below the Popup appears this statement: “The information being requested here is required by windows to schedule the task on this computer.
The information will not be retained by this application.” I am lost due to this because I had already removed the user name and password from my laptop. On trying the old username and password, they were rejected.
My operating system is Vista and there is adequate space to accommodate the software I am trying to install.
I am worried on what to do.
Could you please advise me on how I can bypass the request for username and password?
I will appreciate your help very much.
