i have...
mobo- ASUS m2n32-sli deluxe
cpu- AMD 64 X2 4800+
RAM- 4gb corsair xms2 dhx
GPU- XFX 8600GT XXX Ed

i'm fine for storage space- just upgraded that
btw, i'm currently running dual screen with vista ULTIMATE 64 bit and my primary 22" monitor supports HDMI

i don't have a big budget so i would like the most effective upgrade for the best value
so what should i upgrade?
thanksThis IA a hard question without at least a hint of what your budget is.keeping it below £100 would be nice (about $145)Another question I'd like to ask, is what do you want to upgrade for/what benefits do you want to see?
Also, what PSU do you have?
From you listing your budget in £, I'd guess you're in England - correct?yeah i'm in england
i have a corsair 620W HX modular psu, so it should be able to cope with an upgrade
my vista system check, not that i believe a thing it says because it says my computer is mainly 5.9/6, tells me that my processor is weakest

i reckon i'd either upgrade CPU or GPU... any ideas?

i also have a spare m2n32-sli deluxe mobo hanging around and a slower processor, but one of the two broke (or maybe both) so if i changed the CPU i could check what one is working and do some tests but that's not high priorityIf you use the pc for any gaming, I would definitely replace the video card. Even if you don't do much gaming, running dual screen, it still may not be a bad idea? Not sure your budget would allow for much of an upgrade though.Cards like the Nvidia 8800GS/9600GSO or Radeon 4670/3850 will fit in that budget. A 9800GT will also scrape in at just over that, 8800GTS 320MB is also available. That's if you want a graphics upgrade, as that is the weakest part of your system now but if you're not much of a gamer, it's not really worth it.
Alternatively, a faster Athlon X2, the 6000+, could be a good upgrade, or a Phenom X3 CPU.
I agree that those are the two areas that would benefit from an upgrade.
The Vista experience score is out of date, it was supposed to get regular updates to take into account newer components but it never has, to my knowledge, so a lot of things will score highly because they were good, compared to other hardware when Vista was released, if that makes sense.i do game quite a lot and my 8600GT can run COD4 on fairly high settings...
would games benefit much from a processor upgrade?
also, i was looking at graphics cards and ATI have more cards with HDMI support than nVidia?
i found a decent processor at £75- PhenomX3 8450
the cheapest decent HDMI graphics card seems to be MSI GeForce 9600GT- its £99, but i'm not sure whether it's just not stated on some descriptions- i'll need to do more research into that.
it's also only £90 for an 8800GTS
i would also prefer nvidia to ati because i've only ever used nvidia cards and i've found them reliable, but i would change if it's better value

EDIT: I'm using www.dabs.com for prices etc. but i found a MSI 9600GT for £88Games would benefit more from a graphics card upgrade than a CPU upgrade, but both would help. However, if COD4 and the other games you play don't take advantage of multiple cores, then that CPU will actually perform slower than your current one.
Not sure about the HDMI interfaces, that will need more research.
If all these cards do in fact support HDMI, and it;s just not stated on some, ehre are my recommendations, from cheapest and slowest to most expensive and highest performance.
http://www.dabs.com/productview.aspx?Quicklinx=596W
http://www.dabs.com/productview.aspx?Quicklinx=5DR2
http://www.dabs.com/productview.aspx?Quicklinx=5BSKchecked up on the 9600GT and it would only support it with an adaptor- which is no use because that defeats the point of it.
looks like ATI are the best choice...

OO, just checked on the MSI Radeon 4670, it also doesn't have HDMI.
it seems like £100 just buys into the HDMI range

now i've just been on http://forum.ecoustics.com/bbs/messages/34579/122868.html
it says that dvi and hdmi are exactly the same apart from HDMI taking audio, which i don't need

seems like i'll be fine with any DVI output now- that could save money
what do you think of http://www.dabs.com/ProductView.aspx?Quicklinx=58J5?

i think if i decide on the best graphics card and processor then i can choose what one would be best

i also found http://www.dabs.com/ProductView.aspx?Quicklinx=52VF
The 9600GSO and 8800GTS 320 are close in performance.
That specific 9600GSO is slightly overclocked, which means it will be slightly faster than a normal 9600GSO, but also more expensive.
The 4670 is also faster.XFX do chare alot for their overclocking, http://www.dabs.com/ProductView.aspx?Quicklinx=5DDX is the non overclocked version.
there's quite a big difference in clock speeds (and price) but i think that the non-XXX edition is better suited to my processor and wouldn't be overkill
it appears that they managed to get it from 580-680 and from 1.8 (from the specs) but everywhere else says 1.4-1.9GHz

so... 9600GSO- normal or XXX? (if not XXX i could get an Inno3D one for even cheaper)
or amd 6000+

www.ebuyer.com seems cheaper for everything- strangely...The 9600GSO is very overclockable, if you want to go into that. I'm not saying XFX's overclocking is useless, just that it can usually be done by anybody else, but your mileage may vary as always. I saw the Inno3D card, was going to link to it when I saw the faster 4670 for a similar price.
Ebuyer is another good site, I found their delivery to be more expensive than dabs though so just check up on that before you buy.ebuyer are offering free delivery so it's okay
i need to make the tricky decision of graphics or CPU...

thanks for all your help and happy new year
You're welcome, enjoy your upgrade and let us know how it works out for you.
I'd say a graphics upgrade will be better for you than a CPU upgrade, but of course ideally both would be nice