Core Temp is an excellent and program to monitor CPU temperatures.  There is no installer, simply run the .exe from your desktop, so it's a small footprint and no fuss.

The uniqueness of Core Temp is that it shows the temperature of each individual core for all processors in your system! You can see in real time how the CPU temperature varies when you load your CPU. Works for AMD and Intel processors, dual core, quad core, or hyperthreaded.

PLEASE NOTE: Download link #1 is for 32-bit.  Download link #2 is for 64-bit.

Version 0.99.4.65 - 23rd January, 2009

Major changes:

Completely rewritten base code.

Core Temp is now available in both 32 and 64 bit versions.

- Add: CPU detection improved, efficiency improved, speed improved, clock speed detection improved.

- Add: Initial support for Core i5 (Lynnfield).

- Add: Automatically detect Core i7/i5 series TjMax.

- Add: Show real-time TDP of Core i7 processors (still needs work).

- Add: Alternative clock speed detection for Core 2, i7 and i5 series and up.

- Add: Support for all currently available and some future processor families. (Intel & AMD)

- Add: Temperature changes color when temperatures hit high levels to alert the user. (Orange = hot, Red = critical)

- Add: Show (!) besides the temperature of a core which hit critical temp as a notification of past overheating.

- Add: Invalid temperature values are followed by (?) for both Intel and AMD.

- Add: AMD AM2+ 65nm processors get a 21c offset to fix incorrect temperature reporting (info from AMD).

- Add: AMD Black Edition processors identified by "BE" suffix after PR rating.

- Add: Display time and date on G15 LCD.

- Add: Complete DPI awareness - Core Temp GUI now scales perfectly with any DPI setting.

- Add: Rewritten algorithm for "Register dump" function, works much faster and more accurate (no ghost devices).

- Add: Redesigned log file system:

1) Settings window allows to start logging when Core Temp starts.

Logging can be toggled on or off from the Options menu or simply by pressing F4.

2) Layout is completely changed. Now it's easy to create graphs and the output is more coherent and understandable.

3) CSV file format is preserved.

4) Each logging session creates a seperate log file named with time and date of session start.

5) Logging is now off by default.

- Add: Register dump provides much more information:

1) Supported instruction set.

2) Supported features.

3) Manufacturing node.

4) Default CPU speed, multiplier range and maximum VID.

5) Bus ratio multiplier.

6) Processor and OS thread counts.

7) Cache: Count and size.

8) Processor topology.

9) PCI register dump also lists device names when "PCIDEVS.TXT" file is added to Core Temp's directory.

Link: http://members.datafast.net.au/dft0802/downloads.htm (scroll down a little)

10) Better output layout, easier to read.

- Fix: Core Temp crashes on Intel multi-processor platforms with Socket #0 unpopulated.

- Fix: Countless minor bug fixes due to rewritten code base.

- Fix: System tray icons do not appear after explorer.exe crash/restart

- Change: Core Temp will now work with A0 and A1 revisions of 65nm Core 2 processors.

- Change: Core Temp will not work on some/all virtual machine software.