Hi Gordon, Here's your answer, and from a very highly respected Microsoft Employee. In fact, what Mark doesn't know about compilers, just isn't worth knowing. His full time job used to be troubleshooting compilers for Microsoft covering the whole of Europe and Africa. George. ________________________________ From: program-l-bounce@xxxxxxxxxxxxx [mailto:program-l-bounce@xxxxxxxxxxxxx] On Behalf Of Mark Long Sent: 25 April 2007 10:57 To: program-l@xxxxxxxxxxxxx Subject: [program-l] Re: Vista - Application Memory Limit The limitation is to do with the CPU address length which in turn relates to the CPU bitness, not the OS. Without hacking headers and forcing high loading of system components, user mode apps are limited to 2GB on 32 bit (but be impressed if you can get over 1.6 GB without a crash). On 64 bit, you are in the terrabyte range. What problem are you trying to solve here please? Thanks Mark ________________________________ Subject: [program-l] Vista - Application Memory Limit Date: Wed, 25 Apr 2007 10:01:24 +0100 From: george@xxxxxxxxxxxxxxxxxxx To: program-l@xxxxxxxxxxxxx Does anyone know what the memory limit is for individual applications with Vista? I believe the total limit for the 32 bit version is 4 GB, but have been asked is there's a limit for an individual application. Needless to say I've Googled and hunted the MS web site, but can't seem to find the correct keywords to obtain a result. George W F Bell, Managing Director Techno-Vision Systems Ltd 76 Bunting Road Ind. Est. NORTHAMPTON, NN2 6EE Tel: +44 (0)160 479 2777 Fax: +44 (0)160 479 2726 e-mail: george@xxxxxxxxxxxxxxxxxxx <mailto:george@xxxxxxxxxxxxxxxxxxx> Web: http://www.techno-vision.co.uk <http://www.techno-vision.co.uk/>