Now that the Office installation is complete, note something interesting: This is the first time in the entire sequence that the Free portion of the Physical Memory bar in Resource Monitor has been over 5 MB. How long do you think that will last? Meanwhile, the misleading Committed Bytes counter has dropped just a little, to roughly 870 MB. But the system is completely responsive.
For more details, see Windows 7 memory usage: What’s the best way to measure?