Dell Inspiron 1545 Notebook- Stuck at update installation?

I had just reformatted this laptop a few days before this problem occurred. The Inspiron was reformatted with Windows Vista, and originally came with Vista. A few days after being reformatted, Windows had to do its usual installation of updates before shutdown, we left during that process. We came back a few minutes later and we found that the laptop is restarting, coming back to a screen which says, "Installing update 3 of 3....100%" and then it will restart it's self again. It does this again and again, a never ending cycle. Is there a way to by pass this and cancel it out or a way or anything? Thanks for your time and help.