Windows 7 64-bit, Nvidia gtx570.
Broken: 2.75, 2.75a
Short description of error
The installer for 2.75 (and 2.75a) is approximately 3x slower to install Blender than 2.74 was, being 3 minutes long vs 2.74's 1 minute. It was also extremely slow 'Computing space requirements' (not in included in the 3 minutes mentioned earlier) which took around 30 seconds.
I understand that new features of Blender will have increased the installer size and would have an effect on the installer, but 3x slower seemed excessively slow to me, particularly on the 'Removing files' and 'Removing shortcuts' parts of the install.
Exact steps for others to reproduce the error
Install Blender on Windows 7 64-bit.