Film Editors/Computer Experts: will upgrading my RAM to 4gig allow me to edit videos in full HD?

I need a computer to edit in full HD, will upgrading my RAM make my Compaq good enough?
it's about three years old, a compaq presario cq40 it used to run on vista but now it's win7.. it has 2gig RAM and i'm wondering if i can edit in full HD with adobe premiere if I upgrade to 4gig

Yes it is
however this laptop takes a very good range of CPU's
it also comes in AMD or INTEL flavours so
it depends on what you have fitted.

it may beneift greatly from a simple cpu upgrade.

if intel based, then max cpu is T9600 2.8ghz very nice
if amd based then Turion Ultra ZM-86 2.4ghz very nice

so what have u got in yours?

note: adobe premiere comes in different versions, so which
version would you be buying?

It's not the RAM that does the rendering of the video but it's the graphics card and the CPU (mainly). So I dont think upgrading it will make that much of a difference. When you try to edit something in full HD, do you get an error message? If yes, can you let us know what the error is? Also, can you watch fullHD videos?

Minimum System Requirements

Processor: Intel / AMD compatible at 2500 MHz or higher
RAM: 1 GB or higher
Sound: Windows compatible sound card
Display: 32-bit color depth
CD recorder: for importing from CD
DVD recorder: for importing from DVD and creating Video DVD
Video capture device: required for capturing
Windows Media Player 11 or higher for WMV video playback
DirectX: Microsoft DirectX 9.0c or later
Administrative permissions for program installation and activation
Internet connection to activate

Windows 7 Recommended System Requirements

Processor: Intel / AMD compatible at 3 GHz single core/1.8 GHz dual core
RAM: 1.5 GB or higher
Video: Windows 7 compatible video card
Sound: Windows 7 compatible sound card