If you also have an IDE CD/DVD drive, you can set the jumper for that to "Master" connect it to the furthest connector from the motherboard connector. Then set the HDD jumper to "Slave" and connect it to the remaining connector. I think this configuration will significantly reduce your HDD performance.
Total idiot with hard drives so could you please explain?
Edit: I already have a DVD IDE drive on top of the connector and a SATA HDD as Master of the whole PC.
I have the IDE HDD in my hand I took of the jumper (the manual says that how I make it a slave) but what do I do next?
Edit 2: I understand what you mean now thanks for the info.