You can assign Handy Address Book to be your default vCard handler.
To view the currently assigned default vCard handler, or to make Handy the default handler, use the menu command File/Options.../Options. This will open the Other Options dialog box.
When Handy is assigned as the default vCard handler you can easily open any vCard (.vcf) file. Just "open" any vCard file, and it will automatically bring up Handy and display your vCard contents. You can "open" a vCard file by double clicking on it in Windows Explorer, or right clicking on it, and choosing Open with Handy Address Book from the popup menu. You can also often "open" a vCard file directly from your e-mail program, if someone forwarded you a vCard file. If the vCard file you open contains a single address, it will be imported, and automatically opened with the address editor. If the vCard contains multiple addresses they will be imported into the current address book, and all the imported addresses will be selected. When a vCard file is "opened" in this manner, Handy will import it automatically. If there are any duplicate addresses, new addresses will be created.
If you decide you do not want the addresses in the vCard file to be included in your address book, just hit the Delete key on your keyboard, or choose Edit/Delete from the main menu. This will delete all the currently selected addresses, which are the ones just opened from the vCard file.
For more control over how a vCard is imported, use drag and drop, or import the vCard file.