Now Core Temp supports Windows Vista and Windows 7(including x86 and x64).

All AMD K8 CPUs are supported starting with the early SH-C0 stepping and up. The latest 65nm BH-G1 and DH-G1 revisions give inaccurate readings.
Intel CPUs based on the 'Core' architecture, meaning all CPUs on the Core Duo/Solo and Core 2 Duo architecture.
But Pentium 4/D CPUs are NOT SUPPORTED!!!
Download Core Temp 0.99.4 here:32 Bit 64 Bit
You can check the checkbox to make Core Temp start together with Windows.