I have windowblinds too (it came with the Alienware) and I don't experience this problem myself.
Try adjusting the ingame resolution before you load the game (use the Options button in the launcher). Perhaps it's having difficulty also due to your desktop resolution, which may be too large.
Asides from this, you can try updating your graphics drivers and see if that helps at all.
£2300. That's, what... $4000? Something like that. Very overpriced, and it came with some initial hardware faults, but now everything is sorted out and it's great.