Hey, I have a bit of an issue. here's the specs for my laptop monitor...

1600x900 hp screen 17.3" 16:3 ratio

and my other one...dell e177a

1024x768...is it possible to get both doing hi-res fullscreen or should I just go out and buy another 17.3" screen with same aspect ratio/spec etc thus meaning I'll have to scrap my current one.

I don't understand what exactly it is you wanna do...you want to run at 1600x900 on your external monitor? If that's the case then forget about it, it's not possible. Do you want to run the monitor at 1024x768 and the laptop at 1600x900? That's possible, just stretch your desktop over both of them. Although it won't look very good.

Which GPU? You can stretch/extend desktop, each will work at its max resolution. Duplicating/cloning obviously won't work very well, since both have to be at the same resolution.

BUMP! So, I didn't want to make a new thread, and the text above is confusing, lol... So, I'm gonna ask a new question.

If my primary display is working on 1280x800 and the secondary is 1080p, is it possible to clone the primary onto the secondary (don't have a full HD TV to try it, so I'm asking).
And, if it's not possible that way, would it be possible if I change the primary to secondary and secondary to primary (so the full HD one is primary)?

The problem probably lies with your17.3 laptop monitor being 1080p and also 16:9. Even if you do put your monitors sides by side, your 17" secondary will be taller, whilst 17.3 being shorter and wider.

What you might want to do is to set them to have the same vertical resolution. (ie. 17.3 -> 1366 * 768 & 17 -> 1024 * 768) or 1920 * 1080 & 1280 * 1024)

Good Luck