Yes pretty sure that is the problem. Your Speccy report shows the CPU idling at 1200mhz at 70 degrees. A few years ago I was using an E6300 overclocked to 3 Ghz (from 1.86 Ghz stock) with just a cheap aftermarket air cooler, an Arctic Freezer 7 Pro. Even overclocked to that degree, it would report idle core temps around 25-30 degrees, only rising to about 50 degrees under heavy load for long periods. They were really cool running chips. 70 at idle is much too hot.
If you have the room for it, the cooler I mentioned is good for the money for a Core 2 Duo system. At the very least, you'll need to refit the stock cooler with some thermal compound. Arctic MX4 is decent stuff. Remove the cooler, and clean out any dust from between the fins. Then using a solvent like acetone or isopropyl alcohol clean all the old compound from both the CPU and the base of the cooler. Then apply a small amount (approximately rice grain size) blob of thermal paste to the centre of the CPU heatspreader and fit the cooler. The pressure from mounting the cooler squishes the compound to where it's needed. Make sure all the push pins are clipped into place securely. This alone should drop your CPU temperature by a significant amount.
Your case and hard drive temperatures as a whole look a bit on the high side (not worryingly so, but higher than I like). It might be an idea to have a good clean out of any dust that might be blocking air intakes, cleaning dust from fan blades and so on. An air duster is good for cleaning hard to reach places.
Edited by jonuk76, 10 August 2014 - 12:47 PM.