Having a strange problem with OW, no one else seems to be having it, where it will not open at all.
It installs fine, patches fine and I can run the launcher to setup everything. Once I click Launch Game or use the shortcut it flashes the screen twice and just sits there. Nothing happening.
I've switched off all background applications, changed the compatability options and tried uninstalling then reinstalling.
Any help would be much appreciated.

Well, can you post your system specs and your OS?
Try updating your graphics driver, or if you have an older videocard, search for the appropriate driver (nvdia and ati drivers are for the newer series of their grpahic cards. While on the site it says that the newest driver is good for all cards, that is not really true.).
Try changing the game resolution. Either lower it with the launcher or use the CustomRes parameter to try higher ones (maybe match it with your desktop resolution).
You can also run it in a window (see the parameters list on the site i linked).
And i don't have any more ideas for now...

Yes of course.
Windows Vista Ultimate 64 SP1
Asus Striker
Intel Core 2 Quad 2.7
2GB Ram
Twin 8800GTX 768MB
WD Raptor 150GB
Anything else needed just ask.
My GFX drivers are up to date. I just tried using CustomRes parameter and running it in a window but to no avail.

Okay, I have no idea for now...
64 bit OSes sometimes cause trouble, but I don't think this is the problem here.
This isn't very likely either, since it installed fine, but check the MD5 sum (topic with the same name).
I will think about more, but until then, try writing to the GOG support team, maybe they have a better idea.
Also, you can try posting your problem on these forums. I tried to search for a problem like yours but found nothing yet.

Ok, cheers for your help exerron.

I had this problem in Cod 4 (call of duty). The sound driver was obsolete and needed updating.
Try setting your comp to only use one of the cores instead of all 4. Many games dont like dualcores/quad cores. Like Rune
The same with the graphic cards. Make the comp only use one when trying to play the game.
The core and graphic part should not be so hard to change. Many older games does not like when the computer is trying to give the game two processors or using two graphics cards. If im not mistaken you should be able do make an easy .bat file that disables/enable the uses of the second card and 3 of the 4 cores.