It would surprise me if AD3 won't run on 4GB, but it's entirely possible if running alongside other virtual instruments.
 
When I was running with 4GB, I could easily hit the limit with some of the larger virtual instruments if I didn't freeze some of the other tracks. Only one library (OTS Rick) was actually flat-out too big, requiring more than 2 GB to load its default instrument. I had to create an alternate .nki with fewer round-robins in order to use the instrument.
 
Maybe somebody who's running AD3 could load it up and check RAM usage? That would tell us whether or not we're barking up the wrong tree. I'm not an AD3 user myself, but I know Superior Drummer can get dangerously close to the 2 GB maximum with enough bleed samples loaded. Does AD3 have memory-tuning features like SD2 has?
 

bitflipper
It would surprise me if AD3 won't run on 4GB

 
Hey Bit
 
We're talking BFD3 here, NOT AD3 (or AD2 even) 
 
Steve

I used to run BFD2 with 4Gb of RAM under XP32 (Sonar 6 - 8)

twaddle
Where has the OP said he got Sonar 7 from the internet?
 

He (or the forum) messed up the quotation tags...
 
"here was the app crash log - i just wonder if my sonar 7 is legit- i had 6 and bought it a time ago, then when i had a guy bre-build the machine he got a copy off the internet of 7 , it will not let me install the up dates ?"
 
So yeah... that would definitely be a problem.
 
To the OP... you could still update the legit copy of Sonar 6 if you have the Serial Number/Registration info. The guy who installed that cracked copy of Sonar was not doing you any favors. He actually broke the law.
 
Hopefully he didn't steal your registration of Sonar 6 for himself.
 
For now, if you still have it, try using BFD3 in Sonar 6. Maybe BFD have put something in their code that prevents it from being loaded into pirated host programs.