Blue Screens (BSOD) can be caused by a lot of different factors. The usual culprits include bad hardware, overheating, weak power supplies and buggy drivers.

First Steps

These are some tips for troubleshooting blue screens errors.

First of all, if you made any hardware or software change on your computer, there is a good possibility that the change could have caused the problem. Common changes that could cause problems include: 

• A change of computer case can mean the power supply could be at fault, or overheating (especially small HTPC cases with insufficient cooling). Try installing your motherboard monitoring software, and monitor the voltages and temperatures. Note: Do not especially trust the temps reported by the software, since on board motherboard sensors usually have an error range of ± 10 degrees celsius. So if you see that you are a bit on the high side, find a better temperature monitor to see what's going on. 
• *Memory  *is often a big culprit of Blue Screens. If you have two or more chips, try removing all except one. If the system is OK, then add your memory chips one by one till the problem reappears. If your system is stable with one chip, but has a problem with all your chips installed, then the memory slots could also be at fault.
• A failing hard drive can also give you grief. To check it, open a command prompt (Start -> Run -> cmd) and then run chkdsk /f. The system will prompt you to run the check after a reboot, tell it yes and reboot your system. If any errors were found, then run chkdks again after booting till they are gone. In the case of repeating errors, then the hard disk could start to be failing.
• New system - If the problem is happening on a new system, strip it down to the bare essentials (motherboard, one stick of memory, no TV or any other PCI cards, one hard drive and no CD-ROM).  Press all cables down on the motherboard (IDE and power). If the problem goes away, start by adding each component ONE BY ONE (did I say ONE BY ONE??) till the problem comes back.. 
• Drivers - finally, try updating all your system drivers in the following order: Motherboard, VGA, Network, Sound card, TV Card

Error Messages

Displaying an Error Message

By removing the automatic reboot, the next time a blue screen pops up, you'll be able to see the error message, so you can take additional steps for your troubleshooting. Windows by default is set to automatically reboot after a blue screen. To be able to view the message, you should do the following:

1. Go to Control Panel -> System.
2. Click on the Advanced tab.
3. Click on the "Settings" button under "Startup and Recovery".
4. On the page that popped up, untick the "Automatically Reboot" check box.
5. Click Ok on all the buttons till everything closes.

Additionally, you can also set the "Write Debugging Information" to None, to save time, as that skips making a dump of the memory (and it's not human-readable, so you need to know how to read memory dumps for it to be useful). 

Deciphering the Error Message

The error message consists of: 

1. STOP message at the top of the screen. This is followed by a hex number like 0x00000009 
2. Description message a little further down. This message is related to the hex number above, e.g. IRQL_NOT_GREATER_OR_EQUAL 
3. .dll or .sys file, along with a memory address almost at the bottom of the screen. If you can recognize some of its name (like nvdisp.dll for NVidia display) this could point you in the correct direction.

You can ignore everything else on the screen, since those are the standard Windows messages for all blue screens. After you write down the three important messages, go to http://www.aumha.org/win5/kbestop.php . This site has a comprehensive listing for more or less all the error messages of Windows, and then you can find yours and see what the message is related. 

When All Else Fails

Usually the 'First Steps' instructions above should be all that you need, but if you still can't find the fault you can always post in the MediaPortal User Forums for more help! 

If none of the above works, you may be looking at a trip to the repair shop. The above instructions are all a home user can do regarding the BLUE SCREEN OF DEATH. 

For further information on blue screens: 

• http://en.wikipedia.org/wiki/Blue_screen_of_death

Tools for Troubleshooting:

• http://www.almico.com/speedfan.php