Before selling, how do I delete all data from the computer?

I want to sell my old computer, so I formatted it and deleted all of the files. However, my friend mentioned that there are data recovery solutions available that can recover data even after the disc has been formatted. He advised me to use Data Wipe Software.  I did Google and found an informative blog that explains the best 5 data wipe software.
Now comes my concern: Will my hard disc be usable after using data wipe software?

You can also use an automated third party Data Wipe Tool to perform the deletion. There are various paid as well as free tools available online that can help you delete files permanently. However, the quest for online search is quite tedious. Therefore, we have highlighted an efficient file erasure program that permanently clears the data from your hard drives and makes them completely irrecoverable.
Read More: Delete All Data from Computer Before Selling