|You apparently have a 2GB and 4GB memory card, but to take full advantage of dual channel memory, getting a matched set of memory (or an exact match for your 4GB stick) will speed things up (assuming Windows 64bit operating system).|
I use Disk Clean Up that is built into Windows 7 periodically, Clean out my browser (Cookies, History, Temp Internet Files, etc) daily, set browser to delete history and cookies on closing (keeping history for 1-3 days isn't bad either), and let Windows 7 manage the defrag automatically.
The registry is usually best left alone.
Use msconfig Start Tab and uncheck all except Microsoft and your antivirus program, Apply and Restart the machine. This will remove many programs from starting with Windows and will speed thing up quite a bit.
Forget overclocking on a laptop.
Your antivirus program can make a great difference in the speed of your system. If you are using a System Resource Hog like Norton or McAfee, changing to Avast Free version will give you better protection and a faster system. I use Webroot Secure Anywhere personally at home and have used their products for many years and find them to have very good protection and far superior to the big names (Norton and McAfee) as well as many others. This latest version from Webroot, is the most invisible protection I have come across. You never have to wait for it to update to finish or complete a scheduled scan to do things since it no longer needs these things (their site will explain it better than I can). Of course you need to pay for it though. [I just noticed they have a nice holiday special deal]
Nothing else I can think of....
You have to be a little bit crazy to keep you from going insane.