Thanks, John. We will try that.

I did wade through some stuff at dell and found the following in answer to the same problem we've been having:

Hi,
This is usually caused by a virus.
I dont know which online scan you tried, but run these and see if they find anything. Let them fix anything they find.

Panda            http://www.pandasoftware.com/activescan/com/activescan_principal.htm

Trojan Scan http://www.windowsecurity.com/trojanscan/

The same person recommended doing the task manager-explorer.exe thing as aove, so we'll try that again, too.