Unfortunately, sudden systems freezes can be caused by many things, which makes it difficult to troubleshoot.
Heat is always suspect. The temps you listed are a bit odd. 40°C is fine, but 60°C for the system is a bit high. What did you measure them with? That said, heat problems usually reveal themselves after the system has had time to warm up a bit. That said, heat is the bane of all electronics so if you have a layer of heat trapping dust inside, removing it is a good idea.
I NEVER trust wireless keyboards or mice. They are great when they work, but often they don't and can cause headaches trying to troubleshoot. So you should always keep a spare, wired mouse and keyboard handy when troubleshooting. If it does it with the wired input devices, you know the problem is inside the computer.
A stressed, slightly out of tolerance, or failing power supply can cause freezes and reboots. I use a
FrozenCPU Ultimate PSU Tester for power supply (PSU) testing when I am away from home. It is not as good as a qualified technician testing the PSU under a
"true" (realistic) load with an oscilloscope or power analyzer, but close. The advantage of this model is that it has an LCD readout of the voltage. With an actual voltage readout, you can better detect a "failing" PSU, or one barely within specified tolerances. Lesser models use LEDs to indicate the voltage is just within some "range". These are less informative, considerably cheaper, but still useful for detecting PSUs that have already "failed".
Newegg has several testers to choose from. All these testers contain a "dummy load" to fool the PSU into thinking it is connected to a motherboard, and therefore allows the PSU to power on, if able, without being attached to a motherboard - great for testing fans, but again, not a true load. Alternatively, you can swap out the PSU with a known good one that meets the computer's power requirements.
I do not recommend using a multimeter to test power supplies. To do it properly, that is, under a realistic load, the voltages on all the pins must be measured while the PSU is attached to the motherboard and the computer powered on. This then requires poking (with some considerable force) two, hard and sharp, highly conductive, meter probes into the heart of the computer. One tiny slip can destroy the motherboard, and everything plugged into it.
Inspect the motherboard for bulging or leaking electrolytic capacitors. These failed or failing capacitors are a common cause of sudden, but seemingly random system lock ups and reboots. The capacitors look like tall soda cans, many of which surround the CPU socket.
All older motherboards, and many of today's less expensive motherboards use electrolytic capacitors containing a
liquid electrolyte. Failing (including flawed and/or abused/over-heated) capacitors literally bulge at the seams due to excessive internal pressures. Extreme (and very rare) cases result in a firecracker type explosion that can really stink up a room. Typically, electrolyte just
oozes from the pressure relief points stamped in the tops of the capacitor casings (seen as a symbol or letter). The electrolyte can be caustic to motherboards and flesh. Look for white to dark-brown, dried liquid or foam on the tops or bottoms of the capacitors. Bulging capacitors are a sign leakage is about to occur.
A motherboard with bulging or leaky capacitors can be repaired, but often it is more cost effective in the long run to replace the motherboard.
Be sure to
first power down, unplug the computer, and keep yourself discharged by touching the bare metal of the case.
And to make sure it is not malware related, I recommend you purge your system of clutter using Windows (
XP or
Vista) Disk Cleanup,
ATF Cleaner or
CCleaner. If you use CCleaner, then during installation, uncheck the option to install the Yahoo toolbar and before first use, go to
Options >
Settings >
Advanced and ensure
Only delete files in Windows Temp folders older than 48 hours is
unchecked.
Note: Ensure you know your site credentials (user name and password) for sites you frequent before cleaning; you may have to login again at next visit.
Then download, install, update, and run
Malwarebytes's Anti-Malware (MBAM) to ensure your system is free of malware. Then do the same for all other computers on your network (everything on your side of the Internet gateway, typically a cable/DSL modem).
Recommended: Click here to scan your PC for outdated drivers
