Windows Installer Loading and Unloading

Hi, I'm using Windows XP Pro on a Dell Laptop. I had a virus, fixed
it....now have a problem with Windows Installer. It continues to load and
unload dragging on my CPU. I open Task Manager and see msiexec.exe loaded,
and another instance of it loading, pegging 30% then unloading...over and
over. I click on both , click "end process" and they go away, then come
back.....over and over. Any help will be greatly appreciated. Phillip