Resource meters tell you what's happening, where, on your computer. It's the sort of thing engineers have to be able to see, all the time, or they get withdrawal shakes. Everyone should have that information, anyway. For instance, you'll see poorly-coded web pages lugging your whole system down with an 80% CPU load; trojans showing up, with that characteristic 7-second intermittent activity pulse as they pop up looking for a Net connection; unacceptable hard drive temperatures that show your fan settings are wrong; and so forth. If I had my way, PC and laptop manufacturers would be forced to install machine-specific utilities of this type by law, under stiff penalties including being hung, drawn, and quartered if they didn't. But then I'm an engineer.
 

TinyResMeter is a big favourite with many users as it's got the history and the right attitude: it does the job with little fuss, and has a skipload of configs if you feel like the exercise. It has most of the data you need, and only a giant app or a manufacturer-specific one will do better. Sure, system temperatures are missing - CPU and hard drive - but it's hard to see how they could be included without manufacturer-specific settings for the sensors, this being hard to get right even for more complex applications of this type. 

The screen shot here shows the low-profile readout placed just above the System Tray. I've only chosen to show CPU load, running processes, RAM use and pagefile use -- but there is a lot more you can display.

Unlike many other monitors, it doesn't consume a lot of CPU utilization in order to tell you your CPU utilization. In addition to CPU usage, you can optionally monitor cache, RAM, page file and swap file usage, running processes and threads, disk space utilization and a number of other parameters as well. Also built-in, is a screen grabber that saves the current screen to disk when you press PrintScreen. How the author fits all this into less than 100KB beats me - Delphi sure is compact. There is a subscription version with more functionality. TinyResMeter will do the trick if you need basic system info, plus a few extra widgets. There are other system resource meters that do more, at the cost of more overhead, and more screen space consumed. 

StatBar is an example of one that has a lot more features than TinyResMeter, but at the cost of a higher resource overhead needed to run the program. Nice product though, and easy to try out as the program doesn't require installation.

Lavalys Everest is the commercial Big Daddy in this field with 100 pages of info, it's probably overkill except for PC manufacturers and modders; but their old free edition (Everest Home Edition 2.20), though now unsupported, is still available from some sources.
 

Rainmeter is a resource meter with a news ticker and weather watch all built in. Originating from Finland, the display is a choice of several separate blue and steel grey mini-displays that you can enable / disable and configure to suit. The usual z order, transparency and clickthoughs are available, and you can fade the displays or hide them in case the GUI reminds you too much of a '90s space shoot-em-up game control. The main difference between this and other meters is the way each data group is available in its own small display. This does have its attractions, as you can just enable the one or two you need.

If ran this on your W2K machine, but it's designed for XP and won't run under W2K unless you download and install a missing DLL, gdiplus.dll. The weather for your location, even though available in the configs, didn't work (temp, humidity etc) but that's no great loss - it's normally grim or even worse, so why worry. The Help didn't work either - whether online or built-in you don't know - so you couldn't work out what various missing readouts were, and/or how to configure them.

CPU, RAM, and swap file use, time and date are available out of the box, plus a small but useful Net bandwidth meter that gives your current upload / download usage. Perhaps the most useful of all though is a larger System window you can open, with plenty of data on system resources like disk use, and with a better bandwidth meter. The developer's site is just a little bit light on help resources and other info you might need, as the program is no longer supported. This meter will suit you if you need basic system data, plus the possibility of more if you can work out how to configure it. The little newsfeed from Slashdot might appeal to some. We know that Rainmeter has devoted followers, so you may well find it suits you.

However, if you have a popular make of PC or laptop, you should perhaps search for a manufacturer-specific resource meter first - there are free ones out there for many of them.

i8kfanGUI for Dell laptops is one example. This type of resource meter will often do more, as it can be targeted to the specific make and model of machine - fan speed control being one aspect. It gives you CPU load, processes, RAM use, and a dozen other parameters. The big advantages here are the CPU and hard drive temperatures - both extremely useful. On top of that you can set all your fan speeds, with cut-in and cut-out temperatures for 4 different profiles, in order to regulate those temperatures. Just perfect. The display is a very neat set of system tray icons. To be honest I don't go a lot on the name, I certainly can't type it correctly on a Monday morning - never mind speak it - but that's a minor issue. The product is A-1.

In the screen shot, the two yellow blocks in the System Tray just below the cursor are the Dell readouts. The left one shows CPU load, the right has system temperature over hard drive temp. You can show many other parameters, in any order or color you like.

 

GLINT Computer Activity Monitor

 i8kfanGUI
Website:
www.diefer.de/i8kfan/index.html
Download page: as above
Author: Christian Diefer
Current version: v3.1
File Size: 1.61MB
License: Freeware (GNU / GPL)
Operating Systems Supported: 32 bit Windows versions from W2K >
64 bit capable: Yes (different version)
Other OS: some workarounds for Linux and FreeBSD
Any special system requirements: Yes - for Dell Inspiron / Latitude / Precision laptops
Portable version available: No
Additional software required : None

Rainmeter
Website:
http://www.ipi.fi/~rainy/legacy.html
Download page: as above
Author:
Current version:
File Size:
License: Freeware
Operating Systems Supported: 32 bit Windows versions from W2K >
64 bit capable: Yes (different version)
Any special system requirements:
Portable version available: No
Additional software required : None