Final answer:
The next step after Windows Boot Manager takes control is to load winload.exe, followed by the Windows NT kernel and critical drivers, leading up to the initialization of the user interface.
Step-by-step explanation:
Once Windows Boot Manager takes control of the boot process in a Windows 7 system with 2 GB RAM, the next step is to load the operating system. Specifically, the Boot Manager reads the boot configuration data and uses that information to load the appropriate operating system kernel and core drivers. This usually involves the loading of winload.exe, which then loads the Windows NT kernel (ntoskrnl.exe) and hardware abstraction layer (hal.dll) into memory. Once these critical components are in memory, the system begins initializing the kernel and loading the system registry hive. After this, it starts drivers that are set to load at boot time, and finally, the system initializes the user interface to complete the boot process resulting in the display of the login screen or the desktop if auto-login is enabled.