Hi Bommster, welcome to 7F!
From what I have read, that theme is fraught with problems especially for x64 systems, nice theme though.
Did you see the notes from your link?
Note : Check x64 system files here : [link] thanks to ~Enzoisamazing
Note 2 : some part of Gizdom Reloaded has been corrupted for no reason,so i'm sorry if some parts weren't changed or some bugs can't be fixed
If you believe you have followed the instructions properly there, and still want to try installing, see: Theme - How to Apply Custom Themes
, and try that patch.
You might want to do a System Restore
to before your recent attempt, you never know what may have happened to your system files.