imac running very slowly

Please click on the link below and read the information there so you can respond with some useful information which will help us to determine what might be the problem. We don't even know what year and model your iMac is, what operating system you have or how much RAM you have added. I also recommend that you download, install and run the free app EtreCheck, enabling full disk access. It will provide a report of what is happening in your Mac. You should then post tat report below under "Additional text". That will allow us to avoid having to ask you a whole lot of questions.