Thanks you so much for your help!
I haven't seen that strange image in a while and my computer is running really fast, like when I first got it.
Here is the junkware removal log:
Junkware Removal Tool (JRT) by Thisisu
Version: 6.1.4 (04.06.2014:1)
OS: Windows 8.1 x64
Ran by Nathan on 28/06/2014 at 17:35:10.16
~~~ Registry Values
~~~ Registry Keys
Successfully deleted: [Folder] "C:\Windows\syswow64\ai_recyclebin"
~~~ Event Viewer Logs were cleared
Scan was completed on 28/06/2014 at 17:41:20.37
End of JRT log
I'm in the middle of the ESET scanner right now. It's found some threats but I assume it will deal with them like the others have.
Again, thanks very much for your help, you have somehow found a "miracle cure" for my computer :D