I downloaded the game, install went fine, but when i start the game up, it just crashes to desktop with the usual error message "This program has stoppped working" I tried launching as administrator, put XP SP3 compatibility mode, launched the game directly from EXE instead of the launcher, but i have run out of ideas, HELP!

There are a few things you can try listed in the "Fixes To Common Problems" sticky thread:

http://www.gog.com/en/forum/the_witcher/fixes_to_common_problems/post1

I've tried all of those and none of them have worked.

So the game has never run? Did you run the INSTALLER as administrator? Even if you did, It might be worth a reinstall just to make sure nothing went wrong the first time.

Can we have some more details on your system? OS, processor, graphics card, etc?

I downloaded the game through the GOG downloader, so how do i run installer as administrator? and specs are :
Windows 7 home premium 64 bit
Intel(r) Celeron(r) CPU E3400 @ 2.60ghz (2 CPUs), ~ 2.6GHz
4GB Ram
HD 4350 512mb.

I know the graphic card sucks but i ran the demo just fine with the settings turned down a notch.

The GOG downloader still downloads an .exe installer, it just gives you the option to run said installer straight from the downloader. To run it as admin, just find it via Windows explorer (you can check the downloader settings to see where it's saving the files) and run as admin, same way you run the game itself as admin.

If the reinstall doesn't work, maybe try adding the tag that bypasses the system requirements check... a long shot though as you ran the demo successfully and the error you're getting is not the system requirements error. Instructions for that fix are in the sticky thread.

Anyone else have ideas?

I installed it as admin and didn't work, and the system requirements thing didn't work either :(

Did anything change on your system since you ran the demo? Can you still run the demo right now? I'm not sure why the full game would be giving an error. Anyone else know what might be happening?

I would suggest updating your graphics drivers but if the demo runs then that's probably not it. But you can give it a try anyway.

I just installed the demo, and its giving me the same error when i try to start it :/

Ah. OK, how long ago was it that you were able to run the demo? Were there any big changes on your system since then?

About 10 days ago, and there no big changes to my system at all :/

Try uninstalling the full game and then see if the demo runs. If it does, then it's the installation of the full game that's causing problems, if it doesn't, then there's something else happening.

Unfortunately, I'm running out of ideas for what it could be. Might be worth updating your graphics card drivers just in case, and you could also try installing the game to somewhere other than Program Files, but those probably won't fix the issue.

Can you run the launcher? Can you get to the options menu from there? You could mess around with those to see if they make any difference.

If anyone else has suggestions they are more than welcome!

try playing the game from the direct aplication and not with the launcher.

The OP has tried that already.

My god, what a day... I starting to think i forgot abut reading. Sorry.