Hello ceced,
Welcome to the HP Forums.
I understand you're getting an error message when trying to use the HP Solution Center on your Windows 7 PC.
I will do what I can to assist you with this.
I was able to find this post: "HP Solution Center cannot run because your device installation is not complete".
Just down the page you will find a "solution" marked. Try the steps suggested in the post by pcwizard and let me know how you make out.
Thank you for posting on the HP Forums.