After finally boosting my pc from a technical perspective so i can play this level, i am now completely stuck on it

Have killed all the SWAT type / Prometheous dudes on the roof and now left with the chopper, which is indestructible

I have unloaded 100's of M60 rounds and M4 rounds into it and not a thing.

The only damage i did to the chopper is lucky shot with M4 grenade launcher, which set one of the rotors on fire, but repeating that feat is nigh on impossible

Could someone please tell me how u take out the helicopter, is there a hidden rocket launcher or something somewhere?

Ignore main part of the Osprey shoot the engines after you've dealt an amount of damage to an engine part of the casing will get destroyed and you'll see a red flashing square shoot this and you'll destroy that engine repeat on other one

Aha,
Cheers i had actually noticed the flashing lights on the rotors, will try and concentrate on shooting that then and see if i can finally progress!

Would have been nice if u could conveniently find an RPG on the roof somewhere, life would be so much easier

Too easy.

"And no one likes it easy. It makes you careless."

Easy = Good Stress Reliever.