Overheating cpu?

Right now my computer is majorly overheating. Just browsing the internet the core temps (Intel Core 2 Duo) are both about 66 degress C. The gpu is at the same temp. When I enter a game with high graphics settings the core temps raise to about 90C and same with the graphics card. I've ordered some MX2 Thermal Compound and it should be arriving any day now. I plan on buying a can of compressed air to get rid of dust and removing my heatsink and reapplying the thermal compound. . Will this fix my overheating problem completely? What else might be affecting my computer?

Thanks

The most likely cause of high cpu temperatures is a poorly mounted cpu cooler.

The stock intel cooler pushpins are notoriously difficult to get mounted properly.
You need to do it outside the case so you can see the back of the motherboard to verify that all 4 pins are through and locked.

You might want to invest in a $30 cooler with a backplate, like the cm hyper212 or xigmatek gaia.

Graphics cards do run hot, but they are designed to tolerate it. Your graphics temperatures are not out of line.

Case cooling can also be an issue. Remove the side panel from your case and direct a house fan at the innards. If your temperatures get lots better, you have identified a case cooling isue.

Sorry, I assumed you had a desktop.

Laptops are more difficult to cool. Yes, your thought on clearing out dust is a great idea. You probably don't need to remount your cooler. It was probably done well at the factory, and there is negligible difference in the cooling effect of different paste formulations.