Graffics Card on the way out?

Or Just gw?

Was in Kama and about to seal a lucritive deal that would have given me 50-100% profit and the screen darkened a bit and my UI vanished and the game locked up (mouse could still move tho), i alt-tabbed out and tried to go back in, and i couldnt, so i ctrl-alt-del and cancelled it, the same thing has happened 3 times in 4 minutes, so is it my hardware, guildwars (needs re-installing) or guildwars serverside?

You need to do some work before you will know the answer.
If a load of people post here with the same problem happening around the same time then server seems likely.

While waiting stress your system and graphics card with some other game or heavy graphics applications to see if you can reproduce the problem.

Graphics card
Overheating
Monitor on the way out

Its not always clear

Check inside your pc and clear out any dust build up that's the most common cause, check esp around processor and graphics card fans.

Well the info. is somewhat limited, but it sounds like a server or isp problem. In any case, get a temperature monitoring program (my fave. is Everest Ultimate, but HWMonitor is simpler and just as effective) and stress your PC with a couple of more graphics intensive games. Post the resulting temps here.

Full system specs are necessary to even try to diagnose your problem too.....