Can I add a graphics card to my PC?

I bought a used Dell Optiplex 755, running XP Pro. System info says its a Intel Core2 Duo CPU - E8400@3.00GHz, 2.98 GB RAM - PAE. Google tells me it has onboard graphics. Not sure of the case size; it measures 7 inch x 16" x about 17". I need to know if I can add in a graphics card. If so, any chance a Biostar V6803GS52 Geforce 6800 GS will work? I ask as I bought one for a custom build I am working on. If not, can anyone recommend a graphics card that will work in my PC? Thanks.

   Skygee,

Not sure of the case size; it measures 7 inch x 16" x about 17"

 

Suggests that the chassis is the Mid Tower type and that the card will fit, you will need though to check to see if the power supply is the original 305W that shipped with the computer when it was new, if it is you would need to upgrade it as the 6800 GS requires a minimum of a 350W.

Your upgrade is dependant on the present PSU I`m afraid, you can`t use the 6800 GS if still the original 305W PSU and it would be advisable to replace the PSU if still the original before considering adding any other out of the box new video card.

Let us know if you need help with how to identify the brand and model name or number of the present PSU.

Edit to add:

System info says its a Intel Core2 Duo CPU - E8400@3.00GHz,

 

Must have been upgraded at some point as the specs here don`t list it as being fitted as standard.