Try Microsoft Edge
A fast and secure browser that's designed for Windows 10
how many days it supposed to take when upgrading from Dynamic ax 2012 FP to R2?
Depending on the amount of customization in non-Microsoft layers (ISV to USR), I would say between a couple of days and a week, but no more than a week, really.
The upgrade itself doesn't take days, but you will need to setup and install the target and upgrade environment, as the RTM and R2 components can not co-exist on the same box/OS.