Without access to the server, is there a way to cancel all workflow instances currently running on a given list (without removing the workflow itself)?
I am looking for a solution that works in SP 2007.
If you're going down the code option, you could have code which gets a collection of all the running workflows, and iterates through them and cancels them one at a time, using code like this post:
You could go to list settings and remove the workflow association completely.
Is the workflow an approval workflow? Usually deleting all the approval tasks from the task list cancels all the workflows. Each workflow instance will get a workflow cancelled event too, which is a rejected status i think.