Hi again everdugo, no worries I will break down your questions and answer them individually.
A USB HDD enclosure would be a device I could use by removing the internal hard drive (HDD?) from the computer and the device would provide a USB hookup so I could copy my files onto another computer
Correct, but not as a slave device that is when the HDD is installed internally as a second HDD.
I have two western digital external hard drives, do you think I could use one of those enclosures to do the job or would it be better to buy a separate unit?
This is good, remove the present HDD and keep it safe, install one of the other HDDs and we can attempt to get you up and running with one of these, you will not need an enclosure if we are successful as you can then install the HDD with all your data on it as a slave drive and then copy all your data to the master drive.
As far as using BIOS to set the CD drive as the boot drive. I will look that up on the windows site
We will help you with this when you are ready.
The PSU is the power supply unit? Just so I am clear enough for you to help, it seemed that the computer was powered on, but that it was in sleep mode and could not be woken up i.e., the monitor, keyboard and mouse were not being triggered by the computer
The psu is the power supply unit correct, but they are more complex than what the average person wants or needs to know in the fact that they discharge various amounts of voltages and amps to various components, this means that part of the psu may seem functional but another part may not, no display is the most obvious and common sign.
I hope this information is helpful and feel free to ask any further questions you may have, if I cannot answer them someone else will.
Can I just make sure you are aware of the difference between an external USB HDD and a USB HDD enclosure, we would need a hard drive to install in your computer for the way I have explained above, here is an enclosure http://www.novatech....nov-hddock.html