Check your startup folder and you should find the shortcut for the Adobe gamma loader. Delete that shortcut or, better yet, move it outside of the startup folder, and restart your PC. That should work. Be advised that Photoshop uses the gamma loader as part of its color management process, so you'll need to execute it prior to starting up and using Photoshop. I'm pretty certain you can execute the gamma loader without a need for a reboot, but others may correct me on that.
Just as a tip, for any items that are normally in the Startup folder but which I don't always want loaded at boot-up, I create a separate "StartupNOT" or such folder. Then, I simply drag the shortcuts from Startup to StartupNOT before rebooting the PC. That way, I have a convenient folder from which to restore items to the Startup folder as needed. Another option is to use a startup manager which allows you to easily select/deselect the items loaded during startup. Depending upon your O/S, you may not have such a tool, but I think all Windows O/Ses since WinME do offer that. Unfortunately I don't recall exactly where that tool is and the system I'm on has it hidden by the domain administrator if I'm not mistaken. I belive it may be an option of the System Information applet in the System Tools.