Hi,
My name is Igor, I have 12 Microsoft MVP awards. It's a pleasure for me to help others and I'll do all my best to help you. I'm sorry you have a problems.
Do you have HDD or SSD? If it is HDD, please check drive's health with third party CrystalDiskInfo tool. If you have SSD, check it with a manufacturer's tool.
And please run Task manager, open Performance tab, select Disk C: at the left and show a screenshot.