Since the HP a705w desktop computer comes with Integrated Graphics, I'm going to assume you are installing a graphics card.http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00255589&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=435558
The above is HP Support > HP 705w desktop computer > Specifications.
(Graphics Card, Video Card, Graphics Adapter Card, and Video Adapter Card, all refer to the same thing)
The expansion slot used for a graphics card is a PCI slot.http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00063244&tmp_task=prodinfoCategory&lc=en&dlc=en&cc=us&lang=en&product=435558
The above is HP Support > HP 705w desktop computer > Motherboard Specifications.
Scroll down the page to the motherboard illustration shown in Figure 1, and the motherboard photo shown in Figure 2.
In the illustration the PCI slots are at the bottom of the motherboard, and are named, PCI Slot 1, PCI Slot 2, and PCI Slot 3.
In the photo the PCI Slots are shown, and are White in color.
You can use any available (Open) PCI slot.
You can use a PCI graphics card. (PCI Video Adapter Card. Same thing)
Suggest you install the software (Drivers) from the CD disk that comes with the graphics card, First.
Turn your computer on, when Windows has fully loaded, install the disk into your optical drive. (CD/DVD drive)
Follow the simple instructions, install the software.
When the software is fully loaded restart your computer. Don't be alarmed as your computer won't use this software yet.
After Windows has fully loaded again, shut your computer down normally.
(Start > Turn Off Computer > Turn Off)
Unplug your computer from power.
Open the computer case.
Follow Anti-Static Precautions.
Your body carries Static electricity.
Static will fry out (Short Circuit) the hardware components inside a computer.
(Processor, Ram Memory, Graphics Card, motherboard chipset, Harddrive, and so on)
With the computer unplugged from power, working on a table, computer case open, TOUCH the metal frame of the oprn computer case.
This action will relieve your body of Static.
Should you leave your computer in the middle of working on it, upon your return be SURE to Touch the metal frame again.
There will be a metal slot cover, installed on the outside frame of your computer case. (Expansion Slot Cover)
This flat piece of metal will cover where you want the PCI graphics card to be.
It has to be removed.
There are several methods that this metal cover will be attached, to the metal frame of the computer case.
The metal expansion slot cover you have to remove, will Not be inline with the PCI slot.
It will be over one slot
Once you attempt to physically install the PCI graphics card, you'll see what I am referring to ]
1) To remove this metal cover look for an + in it. A flat tipped screwdriver is installed in the +, and the screwdriver is tipped down.
(The handle of the screwdriver is tipped down)
Looking at the back of the computer the expansion slot metal cover is horizontal.
The cover is twisted in an up, and down fashion to remove.
(Twisting from the bottom of the computer, towards the top, and then back down again)
There are small metal tabs that hold the metal cover in place. You are twisting the cover to break these metal tabs.
2) The metal cover is held in place by a single Philips head screw.
Remove the screw, remove the metal expansion slot cover.
3) I don't believe the a705w had a cover plate. A cover plate is hinged on one side. Usually a single screw is removed, and this allows the cover plate to swing to one side.
This action allows removal of all expansion cards installed.
Once the metal expansion slot cover is removed, line up the contact pins of the Video Adapter Card with the PCI slot.
Insert the video adapter card straight down in the PCI slot.
Install the screw that holds the video adapter card in place, to the metal frame of the computer case.
Close the computer case.
Plug your monitor into the video adapter card.
Plug the computer back into power.
WAIT 1 minute, turn the computer on.
For questions please post in a Comment.