What function does the CHKDSK utility perform?

The CHKDSK utility is designed primarily to check the integrity of the file system on a disk and identify any errors. When executed, it scans the disk for issues such as bad sectors, lost clusters, and directory errors, and attempts to fix any problems it encounters. This process helps maintain the health of the disk and ensures that the file system operates correctly.

By focusing on verifying and repairing disk errors, CHKDSK plays a crucial role in preventing data loss and improving the overall performance of the system. This utility is especially beneficial after improper shutdowns, hardware failures, or other disruptions that may compromise data integrity.

The other options do not accurately represent the function of CHKDSK. For instance, encrypting data for security involves different utilities designed specifically for data protection, not error checking. Similarly, defragmenting the hard drive and removing unnecessary files are tasks performed by other system management tools that optimize storage space and enhance performance, whereas CHKDSK focuses solely on checking and fixing errors on the disk.