|Run msconfig and go to the Start Tab, uncheck all except Microsoft and your antivirus program, Apply and restart the machine (you can add back any program later if you find you need it always on). This will remove many programs from starting with Windows and running in the background. If this makes a significant difference, it will also improve battery life.|
It may be obvious to many, but I have to ask, are you using the 'laptop' on a desk or hard surface or on your 'lap' or bed? Using a laptop on any soft surface will block the bottom vents and any along the bottom of the sides and cause a raise in temperatures. Use it on a desk or get a laptop cooling pad with short legs and a fan to bring the air under the machine. Even of you DO use it only on your desk, a cooling pad with fan may offer some help.
I assume that when you cleared out the heat sink and fan area you also made sure that there was no dust or debris blocking any of the vents or other cooling ducts.
Make sure that Windows power settings are set as for a laptop and not for a desktop.
Reset BIOS to defaults or 'optimal settings' if this is available, then check in BIOS set up that all power saving features, CPU, and memory settings (at least) are correct.
Take it slow and try these in order to see what/if any has some effect and if it is significant enough, then go on. If there is little or no help here, then you may need to reset (or have it done professionally) your heat sink (cleaned and with a fresh application of the correct amount of thermal compound). Again, if you are not knowledgeable about this, ask for advice, if you are not comfortable doing it, get help from a pro. This is your last stop and should only be done if you are sure the heat is not getting out of the CPU fast enough (thermal transfer) or nothing else helps.
You have to be a little bit crazy to keep you from going insane.