I started my PC it was very slow. I checked the task manager I saw that Antimalware Service Executable was taking up a lot of the CPU and Disk %. I restarted my PC and then turned it back on. It was still very slow, I became worried that I might have interrupted a update for windows defender so I tried to check for updates. when I click check for updates it tells me protection definition update failed. I followed this thread telling me to start command prompt and run it as admin then type DISM.exe /Online /Cleanup-image /Restorehealth after that I typed sfc /scannow. It didn't work in normal mode so I started in safe mode because the thread said so. It worked in safe mode and said that no files were corrupted. My PC is much faster now but windows defender still doesn't check for updates and gives me Protection Definition Update failed. I have read something on manually install the updates. Should I try that out then check for updates again? and if so how should I go about manually installing the updates. thank you very much for taking your time to read this and hopefully help me.