A network error occurred while attampting to read from the file "[installer path]"

[installer path] is usually pointing to the installer file, even though it is on the C:\ drive.

To fix, download a Windows utility called MS Installer Cleanup (msicuu2).

Install the utility, then run it from Start > Program Files. You will see entries of the Windows install DB, then just remove the entry of the program you are having problems with.

Afterwards, proceed with installation.