Hi Hagit - welcome to the forums!

Well, of course your computer already has a graphics "video card" of sorts - it's an integrated HD 4200... which as you already guessed, is about as entry-level as you can go. Of course, so is the whole computer - I know it's rather "new", but that's an extreme budget PC from the ground up (no offense intended of course ). It's questionable whether it makes any sense to sink more money into it... it's just not a great computer for Revit to begin with. If you want to do "serious" Revit work on it, you should consider scrapping the whole system and starting over.

But, for starters, have you tried running Revit on it? There's no reason that Revit/AutoCAD shouldn't at least "run".

Okay, so let's say you don't care whether it makes sense or not to buy a new video card to stick into it - you just want to know if you can...

The "sort-of" good news is that you should be able to add a video card to the computer. According to the specs for the P6710f, it has a PCI-e x16 slot for a video card.

The tough part is that the computer has an extremely meager 250W PSU (power supply unit). Adding a mid to high-end video card is going to tax that PSU to the max - and maybe push it over the edge (resulting in regular crashes of the system). So, then you're faced with possibly having to upgrade the PSU as well (you'd have to check with HP whether that's even possible). Also, a lot of those low-end PSUs don't have the proper connectors for the graphics card (many video cards need additional power connections). You might be able to squeeze by with one of the lower-power versions of the HD 5770 512MB.

I know that's not what you were hoping to hear. I'd see if you can make do with what you currently got, and look to getting a new computer if you're serious about Revit.