VS 2008 Extracting Information From Websites

I'm currently using a webbrowser control to extract information from multiple websites. At any given time, my application could be searching through 1-80 different webpages across 1-4 different websites. On my computer, it runs pretty quick. I could go through all 80 sites in just a few minutes. But when on another machine with fewer resouces, it runs awfully slow. Taking up to 15 minutes. Which kind of beats the purpose, but not entirely, of my application.

I'll begin by explaining my methods, and go from there. When utilizing the Webbrowser control, I use While statements and Application.DoEvents, instead of the Webbrowser controls's DocumentCompleted event. I'm wondering if this is one thing that could be slowing down the process. Though I'm not sure why it would be. Also, would utilizing separate threads help with this? I can't imagine it would boost performance. But I'm not entirely sure. I think it bogs down because the application uses so much memory when running. On idle, the application uses about 9.5k memory. When running, I've seen it go as high as 110k.