Not a problem, Dawn.
HP Support > Pavilion a1514n desktop computer > Main page,http://h10025.www1.hp.com/ewfrf/wc/product?product=3207937&lc=en&cc=us&dlc=en&lang=en&cc=us
Product information > Product specifications > Motherboard specifications, RC410-M (Asterope 2)http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00714533&tmp_task=prodinfoCategory&cc=us&dlc=en&lang=en&lc=en&product=3207937
Scroll down to the motherboard illustration, and motherboard photo under it.
A) 24-pin ATX main power cable:
Look to the right of the Ram Memory slots, DIMM 1 and DIMM 2.
Look at the rectangle with ATXPWR1
Scroll down a little to the motherboard photo.
To the right of the black Ram Memory slots, with the white Locks on each end, is the 24-pin ATX main power cable connector on the motherboard.
Whitish connector with 24 socket holes. Two columns of 10 socket holes.
This is an example of an average 24-pin ATX main power cable, and it's respective connector on the motherboard,http://www.playtool.com/pages/psuconnectors/connectors.html#atxmain24
[Note* Color of connectors does NOT matter ]
Note the power cable connector in the middle photo, and the photo to the far right with the power cable plugged into the motherboard.
Note the Lock on the side.
The Lock has a hooked end that goes over a tab, on the motherboard's connector.
The Lock operates like a see-saw on a playground.
Squeeze the top of the Lock in, to bring the hooked end away from the tab on the motherboard connector, when removing the power cable.
When the power cable is plugged into the motherboard correctly, and properly, the Lock will be locked over the tab.
B) 4-pin ATX +12 Volt power cable:
The Processor socket is represented by LGA775.
To the left of it is ATX12V
In the motherboard photo it is the square whitish 4-socket hole connector, to the bottom left corner of the Processor socket.
This is a general example of a 4-pin ATX +12 Volt power cable, and it's respective connector on the motherboard,http://www.playtool.com/pages/psuconnectors/connectors.html#atx12v4
Note that it has a Lock also.
That's it for power cables that plug into the motherboard.
Product specifications specifies that the harddrive is a SATA unit.
It uses a SATA power cable from the Power Supply,http://www.playtool.com/pages/psuconnectors/connectors.html#sata
Note that a SATA power cable's connector has 15-pins, and has the longer connector when compared to the SATA data cable.
The SATA data cable's connector has 7-pins.
Example of a SATA data cable, it's connector, and matching connector on the motherboard,http://en.wikipedia.org/wiki/File:SATA_ports.jpg
Note the SATA data cable connector, and it's matching connector on the motherboard have an L-shape key.
So does the SATA power cable, and whatever it plugs into.
(Harddrive / Optical Drive )
This is an example of a 4-pin standard Peripheral power cable.
Has been misnomered as a 'Molex' power cable,http://www.playtool.com/pages/psuconnectors/connectors.html#peripheral
IF, your SATA harddrive has a provision for a SATA power cable, AND a 4-pin Peripheral power cable, ONLY use just the SATA power cable.
Using both will burn up the SATA harddrive.
(Maybe not right away, but I assure you it WILL happen)
Do not use just a 4-pin Peripheral power cable on a SATA harddrive.
NOT enough power.
The Optical drive (DVD burner) is not stated whether it is a SATA unit, or IDE. (PATA)
If it is an IDE (PATA( unit it will use a 4-pin Peripheral power cable
It will also use a 40-pin flat ribbon data cable,http://en.wikipedia.org/wiki/Parallel_ATAhttp://en.wikipedia.org/wiki/File:PATA-cable.jpg
[May be 39 holes with 1 hole blocked off ]
CPU_FAN on the motherboard up above, and to the right of the Ram Memory slots, is where the Processor fan plugs into.
SYS_FAN below the processor socket, and to the right of ATX12V connector on motherboard, is for a computer case fan.
A computer case fan can also use a 4-pin standard Peripheral power cable, with an adapter cable, or may use a 4-pin small Peripheral power cable,http://www.playtool.com/pages/psuconnectors/connectors.html#floppy
This power cable is also used for a Floppy Drive, and for newer computers is used on a Card Reader.
For additional questions please post in a Comment.