If your Windows version is 32-bit, use the register32.bat file.
If your Windows version is 64-bit, use the register64.bat file.
Not sure if you're using a 32- or 64-bit version of Windows?
Simultaneously press the Windows and Pause keys on your keyboard. Alternatively, click Start > Settings > System > About. The displayed window will tell you whether your Windows version is 32- or 64-bit.
Right-click the appropriate file and save it to your Desktop.