I unplugged the sockets going from my hdd/cdrom/dvd rom and plugged them all back in.
Now I'm in an even bigger mess, the cdrom and dvdrom are not being read at all when I go into my bios. I have the 'system' cable plugged into the motherboard - which the 'master' socket connects into the dvdrom.
One of the little pins on the back of my dvdrom has been badly bent, this could be why it's not being read... anything I'm missing? And I've already checked to make sure the power is connected to each hardware device.
The hard-drive is being detected, but is still coming up with 'disk read error' - I would love to run some bootup utilities, or even try to re-install XP. But I can't as both my cdrom and dvdrom aren't responding at all. =/
Well if it is being detected in your bios it has power. So my guess would be either it's plugged in incorrectly, bad hard drive, or motherboard. Since the hard drive is a Seagate it is still under warranty. Usually Seagate's have a 5 year warranty. When you boot your computer do you hear the hard drive spin up? Is it making any strange noises that you haven't heard before?
Unplug the ide and power cables from both the cdrom and the dvdrom, then see if your HD boots. I am a bit suspicious of that 'bent pin'. Maybe also try a new ide cable for your HD, and check your MB's ide connectors for any further 'bent pins'.
I appreciate your attempt to try to fix your system yourself. As it would appear that you are in a downward spiral, I suggest you have your system assessed by a professional computer technician. They will most likely be able to assist in undoing the damage that you did yourself.
With respect to your failed hard drive, I suspect that it has failed. The computer technician should be able to help make that determination and possibly assist getting your data off that drive. If they determine that your drive has failed and requires data recovery, you may want to have it assessed by a hard drive data recovery lab.
All in all, it really depends on the value of the data on the hard drive. If you don't care about the data or your system, then use it as a learning experience. If you are simply concerned about getting your computer back up and running use a service technician. If you are concerned about your data, contact a data recovery lab and a service technician.