How do I know how much swap is used on Windows 7?

Solution 1:

The Performance Monitor (perfmon.exe) has counters for the page file usage.

1. Load it up by either running "perfmon" on a command line, or by selecting "Performance Monitor" under Administrative Tools.
2. Expand "Monitoring Tools" in the left column and select "Performance Monitor."
3. Right-click on the graph to the right and select, "Add Counters."
4. Scroll down the list of available counters to "Paging File."
5. Click on the down-arrow icon to the right of "Paging File."
6. Click on "% Usage" under "Paging File" and then click the "Add" button to put the counter under the "Added counters" list on the right.
7. Click the "OK" button.

The graph will now contain a line for the page file utilization percentage.