Perhaps what our esteemed friend hoongadoonga overlooked asking when he posted, is whether you still have your original download of the game (backing up the download is recommended; if you didn't do so already, make sure you do when this is all sorted).
But, if you just bought it, you should have no trouble downloading again via Avangate using your order number/link - I believe you get several downloads over a period of time. Check the confirmation email you got/Avangate website for info.
That failing, OBD will almost certainly help you if you contact them via the support email.
HTH
Yes, thanks it does help and my apologies for coming over a bit grouchy, the problem's getting me down now.
I've only just bought it so I have my email and link...I realised after my previous post.... Re-Installed it all and lowered my settings, etc, as recommended but now it's worse than before.
It still won't end a mission but now the flight is jumping and stuttering where before it was smooth.
My main concern is the paragraph about them not guaranteeing it running on a laptop, even though I know it has more than enough grunt for the job... It's specs are way above those recommended and it powers through ROF and IL-2 without blinking.
I can keep uninstalling/Installing but I'm starting to worry it won't help... l have made sure Direct X9 is installed and the latest patch for Windows 10.