Scary noise and crazy colors/pattern on screen, then restarts. Please help!

[CarMel83]

Hi,

My name is Melissa and I'm sorry If I have posted this in the wrong place. My friend Kevin is good with computers and told me this was the best place I should go to ask, so here I am.

My computer will randomly (sometimes after and hour, sometimes after 3 hours, sometimes after 15 minutes, it locks up, sometimes making a scary noise, and also either makes a bunch of crazy colored patterns, or black screen and then restarts. It will also go to a screen my friend calls the "blue screen of death." (more scary!)

Please help, I know it only takes a minute to restart but it can be sometimes inconvenient and would love to get it worked out. Thanks!

Sincerely,
Melissa Bennet

 

[Onus]

We need to know the components in your PC to make the most relevant suggestions. Also, does it matter what you are doing, for example does it only happen when you're playing games, or does it happen even while you're just surfing the web, or reading something?
High on my list of suspects is your RAM. Download and burn memtest86+ onto a CD, boot with that, and test your RAM. Test only one stick at a time. One of them may be bad. If you have Windows 7, it has a memory test program that may also find this problem. Repeat the test separately with only one RAM stick installed at a time. Make sure you turn off your PSU with its switch or unplug it before you add or remove any parts, as even when your PC is "off," the PSU will be sending +5V of standby power to it.
If this happens only when you're playing games, another suspect is heat. Make sure all your fans are running, and that your system has not become clogged with dust, pet hairs, or dead bugs. If so, clean it out with a pressurized duster, NOT a vacuum cleaner. Vacuum cleaners create destructive static as dust whooshes up their hoses.
A third possibility, again more likely if it happens when the system is under a heavy load, is a bad or failing power supply (PSU). What brand and model (not just wattage) is it?
The more you can tell us about your system and the parts in it, the better we can help you.