Final answer:
One way to encrypt the laptop's hard drives without purchasing any additional hardware is to use full disk encryption software such as BitLocker or FileVault.
Step-by-step explanation:
One way to encrypt the laptop's hard drives without purchasing any additional hardware is to use full disk encryption software such as BitLocker or FileVault.
BitLocker is a built-in feature in Windows operating systems that allows you to encrypt the entire hard drive. It uses a symmetric encryption algorithm, such as AES, to protect the data. To enable BitLocker, go to Control Panel > BitLocker Drive Encryption, and follow the prompts to set it up.
FileVault is a similar encryption solution for macOS. It encrypts the startup disk and all data on it using the XTS-AES-128 encryption algorithm. To enable FileVault, go to System Preferences > Security & Privacy > FileVault, and click on the lock icon to make changes.