Please restart your CPU slot, set it to finish so it not get a new WU if you don't want. But please doing harm the science in not finishing WU. It will also harm you passkey, keep in mind the required 80% success rate.
To make it more secure you can configure the CPU slot with an advanced option "pause-on-start" set true. Will not start the slot after reboot.
But please: finish work started.
It starts automatically when the program first starts yet we are told to pause the CPU slot because of bottleneck risks...
Well it really depends on your system isn't it? I have 2 gpus in a decently fast quadcore system so I don't need to disable anything.
So what you should do if you are indeed have bottlenecking issues, set it to finish first. Then when the WU is finished, go to the configure menu -> slots -> remove cpu.