Our server had rebooted while QW was running and now we are getting the above error.
You know, 9 times our of 10 this message just means you started QuoteWerks twice. Either look for the login screen, or kill it with task manager on the workstation - unless you're running from the server (like citrix or terminal services, it's not the server.
If you ping me an email, I'll reply with a link for a screensharing session. I'm sure it'll be something really quick. email@example.com
Do you have a qw.exe reference in Task Manager hanging around? Kill that and try again.