This is a handy tweak if you merge a lot of older registry files. If you are merging registry that was designed for a 32-bit app on a 64-bit Windows, you might want to use this.
It adds an option to the right click menu of .reg files to merge using the 32-bit version of regedit instead of the default 64-bit version.
This is for 64-bit software.
Only use this if you are using a 64-bit version of Windows.