Hi, and welcome to the forum:

What model and operating system (XP, Vista, Windows 7) are we talking about?

Dell has in recent years included a Utility partition to return a computer to its "as shipped" state; if you are using XP the instructions are here:
http://www.goodells.net/dellrestore/

Dell no longer ships Re-installation disks. See  here:
Media Reduction Initiative (effective April 1, 2010)
http://en.community.dell.com/support-forums/desktop/f/3514/t/19332656.aspx

I would recommend reformat/reinstall of the operating system. To add to Joe's instructions, if you want to try restoring to factory settings:

Win7 factory restore:

http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?docid=362066

Vista factory restore:

http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?docid=336966

XP factory restore:

http://support.dell.com/support/topics/global.aspx/support/dsn/en/document?docid=181316

Hi Bugbatter:

Just checking out these links with the idea of saving them, but what appear to be buttons to push all have red X's on them. I wonder what might be causing this.

what appear to be buttons to push all have red X's on them

They're looking fine today...not sure what was wrong yesterday.