error message

When I boot my machine, I get to desktop but there's an explorer error box and when I hit details it says Kernel 32 dll.  I've looked at numerous articles but I'm still confused what the problem is and how to solve it.  I also went to control panel and look at systems, then device manager.  In the line up I have a yellow questions mark under unknown device and the sub-yellow question mark has a red X through it.  Is this important because Dell tells me to ignore it, it's not important.  Thanks for any advice.