Hi,
I've written the following information up many times on the forum and it is the method I use.
1. I have WinRAR, a 30+ day version is available free I believe.
2. I place the PD installer into WinRAR and "unpack" the component parts of the installer.
3. I then select "setup.exe" from the newly created folder and install PD.
The advantage of this method for me is,
a) I don't have any multiple corrupt files circulating in the temp directory.
b) The folder asis can be stored onto a disc and is less likely/wont have an unpacking problem (I used to get that with installer packages).
Dafydd