AVG Anti-Spyware copy failed upon trying to install

Trying to install AVG Anti-Spyware 7.5 on a computer that is heavily infected with spyware.

It goes through the very first part of the installation and then stalls. When you click on see details it says that: 

Copy to C:\Program Files\Grisoft\AVG Anti-Spyware 7.5\Reports

Copy failed

It then goes on to try and copy the Quarantine folder but stalls there again.