My computer refuses to download anything I try, it claims every download is corrupted, fragmented, and is potentially dangerous for the computer, yet I was only redownloading a program I had on the same computer before and there was nothing wrong with it. Now the computer will not download anything else (it makes the same claim as with the original download) nor will it allow me to update/upgrade drivers or other programs. ALL downloads are failing. I have run antivirus, antimalware, and defrags, nothing has been helping. Internet also has become very slow, what can I do?