Be really sure that your db files are not compressed first. Right click on both the db files and the logs for all DBS (especially those that are system db's but basically any you want to use) go to properties then advanced and un tick the box that says compressed. Using certain OS cleaners will compress the files on your hard drive including db and log files. This causes them to behave as though they were corrupted.
If you have db's that you...

Maybe this post will help you?
https://community.office365.com/en-us/f/172/t/266070...