Recently had a lady with a sony laptop that had a faulty fan and was overheating and resetting. This was a known fault with these laptops, and sony repaired the laptop free of charge even though the warranty had expired. All that had to be done was to ring them and then get it sent to Auckland. So if your sony laptop is overheating and resetting itsself then give the sony support center a ring.
The Sony Vaio VGN-CS16 has a known issue with the fan being faulty and making loud noises, which can cause the laptop to overheat and restart itself. Laptops experienceing this problem will be repaired by sony even if the laptop is no longer under warranty. You should contact your nearest sony service center for more details.