Windows 7 and memory utilization

[TechnoPro]

I'm looking for an easy way to determine if a Windows 7 system has enough RAM installed to handle the OS and whatever software load the user is placing on it.

I'm a few generations behind in that I only know the Windows XP spot-check method: Task Manager, Performance tab, and compare various numbers from Commit Charge with Physical Memory.

I'm at a loss at what numbers are the same in Windows 7. Resource Monitor -> Memory tab, under the Physical Memory chart: what would tell me if I ran out of physical memory and was hitting the swap file?

Any help would be greatly appreciated.

 

[lxskllr]

I'd say when Cached=0 is when you're hitting your page file.

Edit:
This is Vista, but Win7 should be similar

Edit2:
When Cached and Free = 0 is what I should have said.