What's wrong with my computer? Can't delete things?

Just a while ago symantec popped up and found a whole bunch of Trojan horses and bloodhound something. They were all located in the app data temp folder. I restarted my computer and I can't delete stuff. It says delete but it just says that for a long time and when I press cancel it just say a cancel and never does. The same thing happens when I tried to delete my Internet explored history. It just freezes and never deletesmit. But I can delete mozilla history and stuff.