Unless you're running really short on RAM, more of it won't really help with latency.
It mainly boils down to your soundcard/interface and (to a certain extent) your CPU.
A high-quality soundcard intended for recording that is capable of low-latency operation is unavoidable, and then the lower buffers required for low-latency operation also increase load on the CPU, hence why a decent CPU is required.
What soundcard do you have?
The link that Kingofpain posted isn't actually true ASIO... ASIO isn't just something that you can install... its a driver model and you need to use the specific ASIO drivers made for your soundcard (if it doesn't have any, that is a sign that you need a new soundcard) for the best performance.
ASIO4All is designed to allow cheap soundcards to be used as if they had ASIO drivers, but this really can't substitute a proper soundcard with proper drivers. It can (to some extent) lower latency because it cuts out some of the high-latency Windows audio systems, but again its only a 'temporary botch fix' at the very best.
Also, many recording soundcards/interfaces have hardware built into them to provide "zero-latency" input monitoring, as opposed to monitoring through software which will always introduce some level of latency (noticable or not).