You know, it would be really nice if you could try and use proper grammar and sentence structure, and try and explain your question clearly - it's really hard to work out exactly what you're talking about, which makes it really hard for anyone to try and answer you. Anyway...
Are you sure you mean the patch which allows 32-bit versions of Windows to address more memory? Because it sounds like you're talking about something completely different. 3.6GBs of memory is roughly what a 32-bit OS can address by default, so I don't think you have that patch installed (unless you have exactly 3.6GBs of RAM, which I doubt).
What it sounds like you're talking about is something totally different. By default, applications running under Windows can each only address up to 2GB of RAM - regardless of how much RAM you actually have, that is the maximum amount they can use (and it includes VRAM too, not just main memory).
However, there is a flag which can be set for an application at compile time (or I think is automatically set for every 64-bit executable) which makes that application "Large Address Aware". Basically, it allows that application to address more than 2GB of memory.
It is disabled by default, and most application developers don't usually enable it since most games don't need it, and it could, in theory, potentially cause compatibility problems. Occasionally some developers release a patch for their game enabling it - a recent example of this would be Skyrim, which initially lacked this feature, but after lots of people complained about not being able to make use of all their memory, had a update released to enable it.
I don't know if HellGate: London ever had a patch made containing that feature - frankly, I don't know why such an old game would need it, and I don't think anyone had more than 2GB of RAM back then anyway. But if that's what you're talking about, then it won't have any impact on any other applications at all - in terms of the amount of memory they can address, or in terms of performance.