Don't worry! Hauptwerk is already 64 bit.
You can easily confirm this yourself:
1. Hold down the OPTION / ALT key on your keyboard, then pull down the Apple menu.
2. Choose “System Information” from the top of the Apple menu list.
3. In the System Information app, scroll down the left-side menu and look under “Software” and choose “Applications”.
4. Look for the “64-bit (Intel)” option in the column header, and click on that to sort the column by 64-bit.
5. Every app that says “No” is 32-bit, every app that says “Yes” is 64-bit.
Best,
Chris