You can use Everest Home Edition to measure your temperatures and PSU readings ('computer > sensors')
Free download from http://www.lavalys.hu/products/download.php?pid=1&lang=en.
Then check your system's power requirements at http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php
Before doing any expensive upgrades, I would first fit a new fan and apply some good quality thermal compound to the CPU.
Post back with your readings and PSU requirements.
Free download from http://www.lavalys.hu/products/download.php?pid=1&lang=en.
Then check your system's power requirements at http://www.jscustompcs.com/power_supply/Power_Supply_Calculator.php
Before doing any expensive upgrades, I would first fit a new fan and apply some good quality thermal compound to the CPU.
Post back with your readings and PSU requirements.