I don't think your 3 year old computer is the problem as I'm writing
this on a 6 year old machine I first built in 2000 and upgraded to an
AMD 2800 CPU in 2005. The RAM was upped to 2 MB several years ago and
I'm running 10.10 on it with no problems. I don't have any computer
newer than 2005 or with more than 2 GB of RAM and have never bought
"premium" components.

However... certain combinations of Mainboard, CPU, RAM and various
adapter cards will give problems with certain operating systems. I'm
being very vague because until the issues crop up nobody can predict
them. Frustrating? Yes, but that's life in the fast lane of the
computer world.

As they say when they don't have a clue, "it's all in the way you hold
your mouth"!