New. Need Help

I'm just starting to learn Unity. It was running fine, then Windows 8.1 happened and now it seems new problems are popping up every time I use it. The most recent one is the most frustrating and I have no idea if it has anything to do with Windows, but until I hear otherwise, I will blame it because that stupid update is when all my problems started.

So, current problem. I get this error:
Moving Temp/Assembly-UnityScript-firstpass.dll to Library/ScriptAssemblies/Assembly-UnityScript-firstpass.dll failed: The process cannot access the file because it is being used by another process.

Now, I'm new to all things programming, not just Unity, so I have no idea what that's trying to tell me. What I do know, is it never used to tell me that, now it is and when I select "Build and Run" it will go so far, but just stop when it would normally start pushing to my phone. I've checked the phone and it is in USB debugging mode. I've restarted everything. Still just stops, no error message or anything. Just acts like it didn't do anything wrong.

Any ideas?

 

The process cannot access the file because it is being used by another process.
Does it help if you disable your AV tool while the Unity tries to build the project?

 

Not sure. How do I do that?

I did find that I can just build the project and manually move it to the phone, but it would be better to not have to do that.

 

That depends about your anti-virus/security tool.

 

Oh I see. I didn't realize you were talking about anti-virus. I will try and see. Thank you.