3.0 hard drive disk

So recently I moved from one state to another and after I set up my PC and tried to look at some files I needed from my Toshiba external 3.0 external drive but I can't access this disk. In windows explorer my drive only shows up if I view hidden items. If I double click on it, it tells me to...

So basically, I uninstalled my antivirus (Norton) to replace it with Avast. After uninstalling, I couldn't install Avast properly. I thought that it was just a bug. I woke up the next day and opened up my PC, and Steam opened up with an error something like this, "Steam folder not writable". I...