Remember to make sure you are selecting the correct operating system (as I am sure you are but just in case) and here is the download for the PSC 1315 Full Feature Software and Drivers for Windows 7 64-bit.
Make sure your Adobe Flash Player is up to date as per this thread.
Another thread for you to check out - which reminds me, which file is the installation saying it can't find?
Final suggestion in this link.
