I have Harman Kardon HK206 Computer Speakers and my Father was deleting programs from our computer and didn't know that he deleted the program that reads our speakers so now we aren't getting any sound. how do I fix this?

The speakers do not require drivers. The software that has been deleted is for the sound card in the computer. Before you do anything on the computer, just double check that the speakers are connected to the correct socket - usually light green colour. Then check that the speakers work by connecting to another source e.g. MP3 player or Hi-Fi or TV. If the speakers are OK then check the PC output socket with other speakers or headphones.
To check the PC drivers, you need to first check that sound card drivers are installed and working.
Click on the START button. Then RIGHT-CLICK on My Computer, select MANAGE. Click on Device Manager in the Computer Management window. In the list that appears in the right-hand pane, click on the plus + sign next to Sound, video and game controllers. Check that no items have a yellow warnig sign and that various audio devices are listed. You should have at least AUDIO CODECS, LEGACY AUDIO DRIVERS, Manufacturer specific drivers (e.g. Realtek High Definition Audio). If the drivers are not there then you will need to re-install them, probably by downloading them. If any yellow warning signs are shown, then that driver is in error and may also need to be re-installed.
You can also try right-clicking on the driver in the list and select UNINSTALL. Then click on Action in the top menu and select Scan For Hardware Changes to try to re-install the drivers.