Photoshop required large memory to function well (1 GB or more is preferable) because it handle image files. Here discussing how to speed up startup of Photoshop.
Each time Photoshop start, all plug-ins (necessary or unnecessary) also load with Photoshop. You can prevent unnecessary plug-ins by loading thus reduce start up time.
Navigate to C:\program files (assuming ‘C’ is your installed directory)\Adobe. Open the directory. Here you can see folder named ‘plug-ins’. Within this folder you find the plug in files, all of which loaded each time Photoshop started.
You can disable plug-ins which you scarcely use. To do this simply edits the name of the files or folders containing plug-ins and insert a tilde (~) before each name. You can always re-enable the plug-ins by deleting the symbol ‘~’.