From MeasureJ2X
Compatibility
MeasureJ2X will run under Windows 7, 32-bit or 64-bit version. When using a USB-serial adapter with Windows 7 64-bit, there need to be 64-bit drivers installed for the USB-Serial adapter. See USB-Serial Adapters for more information.
To be more precise, the underlying Java used to run MeasureJ2X (distributed by Oracle/Apple/Sun) is a 32-bit version, so MeasureJ2X will run in 32-bit mode under Windows 7 64-bit; the 32-bit mode is enabled by default in Windows 7 64-bit.
