How to customise Task Manager
Task Manager's Processes tab shows CPU, Memory, Disk and Network by default. Above these headings are percentages so you can see at a glance whether any is maxed out. It isn't obvious, but you can right-click on any of these values to display a list of extra attributes that you might want shown.
Tick Command line, for example, and you'll be able to see where the app or process is located on your disk.
At the bottom of the same menu is Resource values. Hover over this and a sub-menu will appear with Memory, Disk and Network. For each, you can choose whether to show percentages or values. By default these are all set to values, but it can be easier to understand the figures as percentages.
In the Performance tab, the CPU graph can be customised by right-clicking and choosing a different view. By default you no longer see how hard each processor core is working, but you can revert to the old way of doing things and see a graph for each core by choosing Change graph to Logical processors from the right-click menu.
Double-click on a graph to switch to a compact 'graph view', and double-click again to switch back.