The one component that is almost irreplaceable in your computer is the motherboard.

Often, once the motherboard dies, it may be uneconomic to repair the computer.

Hence it is important to choose a computer with a good robust motherboard.

It is a bit like laying a good foundation for a house. If the foundation is shaky, it doen't matter what quality the other parts are, your are likely to be heading for trouble.

The motherboard is the main printed circuit board in your computer. Everything plugs into the motherboard. Motherboard design is evolving so rapidly, that it is often impossible to buy replacement motherboards as little as two or three years down the track from their initial release. This means that if the motherboard fails, and a replacement cannot be sourced, then a more modern motherboard has to be fitted. Because the more modern motherboard will probably not support the existing CPU or memory, these components must also be replaced. Now we find that the power supply is no longer big enough to drive the new CPU, so it too has be to upgraded.

Good motherboards have

1. A good robust mechanical design
2. Well tested chip sets
3. High MTBF

Poor motherboards have

Poor mechanical design - poor or thin circuit board

1. Poor chip sets
2. Low MTBF

Good quality motherboards cost more than the poor quality ones, but are much more reliable.

I can advise on the motherboard quality used in most PC's available today.