quiet_killer: there is more than one reason that foce your windows to pull you out that message !
1 - a program has messed up your windows and now your getting this message
2 - you computer is all messed up and the memory or the HD has been defect
solution:
1 - formating the HD and reinstalling your windows usually solve that problem.
2 - try and clear your cache then redownload the game. (that actually never work, but you can try if you don't want to lose your data by formatting)
3 - reinstalling the browser can solve the problem too, but it is considered better if you upgrade it to the latest version.
if you wanna know why i know these...
it happenned to me lots of time !
here is something you can try out too...
when the window appear, put it in a corner you don't need !
and try to play the game anyway ! when it happenned to me
like the last time, i did this but i could play the game even
with the error message on display !
glad i could help !