I have had my computer for about a year and its running fine, the temperature of the CPU has gone up since when i got my computer. I know this is supposed to happen, but I was just wondering if you are supposed to apply new thermal paste to your CPU, and if so how often you should do this. Thanks

generally new paste is a bad idea as old paste is better as it is "bedded in" - so long as the CPU temp is 50-70 degrees centigrade then its ok

You may want to consider taking a can of compressed air and blow out the dust on the HSF.

replacing the paste is a-ok, it gets burned out with time, and Intel's native coolers don't have such a good paste on them to begin with. I've had the same problem with my computer, and I bought a new CPU cooler, some Zalman $40 model, scratched the old paste off the CPU, and applied the new one with the new cooler. It never topped 50c since.

Good point. Chances are there is a lot of dust preventing the heatsink from cooling like it should. Try that and recheck temp.

You may want to consider taking a can of compressed air and blow out the dust on the HSF.