Why launcher.exe process takes only about 1gb of ram??

[Feuerfalke]

No gaming software uses your full RAM.

If at all, it's reserved half of it unless you enable a 3GB-Switch or assign more memory by other means. However, that does not necessarily increase performance.

In general, Windows offers 2 GB to any application, no matter if you have 4 or 64 GB of memory installed.

Only exception is a 64bit.exe running on a 64bit OS. In this case, it CAN use more RAM. But again, this will not increase overall performance. If you notice a difference, it's by improved loading times and less texture-loading while inflight.