It's actually recommended by most computer repair shops to do :\
Actually, they say this because they know most people are incapable of properly maintaining their computer. If you spend time in researching this area of computing, you will find that you can easily use the same system for a certain number of years before it starts to show signs of wear and tear.
the laptop is not over heating (it never does for some reason)
Errors during setup I have encountered so were due to overheating computers.
Test both your RAM and HDD with diagnostic software.
One thing that I always suggest is to properly reformat (Full, not quick) the HDD/partition. (Preferably the entire HDD) however, I have yet to see any proof that this matters. In the case of a virus, it is more safe to do so but does it actually matter during the installation progress? Any theories on this?