I have a reasonably fast computer with Core 2 Quad Q8200 CPU, 4 GB ram, Seagate 7200 rpm drive. But when I open Photoshop it takes about 15 seconds to open and additional 8 sec to become responsive.
I want some suggestion to make the launch faster.
Check your 'Scratch Disk Settings' in Edit > Preferences
The primary scratch disk drive should have decent amount of free space, add some secondary drives as scratch disks
It should run faster now !!!
When using another Adobe Product, Premiere, I've enhanced performance all around by increasing my page file size. See if that helps you.