Q: I erased the disk, went to reinstall OS x, but when I select "Macintosh HD" and try to advance with the "install" button, it won't let me. Has anyone had this issue before? Any suggestions?

You need to be more specific and provide useful detail. Otherwise we cannot properly diagnose your problem. Please provide detailed steps for what process you have followed and detailed error messages, if any. "Won't let me" isn't very helpful.

Follow these steps:

Install or Reinstall OS X from Scratch

Boot to the Recovery HD:

Restart the computer and after the chime press and hold down the COMMAND and R keys until the menu screen appears. Alternatively, restart the computer and after the chime press and hold down the OPTION key until the boot manager screen appears. Select the Recovery HD and click on the downward pointing arrow button.

Erase the hard drive:

  1. Select Disk Utility from the main menu and click on the Continue button.

  2. After DU loads select your startup volume (usually Macintosh HD) from the

      left side list. Click on the Erase tab in the DU main window.

  3. Set the format type to Mac OS Extended (Journaled.) Optionally, click on

      the Security button and set the Zero Data option to one-pass. Click on

      the Erase button and wait until the process has completed.

  4. Quit DU and return to the main menu.

Reinstall OS X: Select Reinstall OS X and click on the Install button.

Note: You will need an active Internet connection. I suggest using Ethernet if possible

           because it is three times faster than wireless.

This should install the version of OS X that you had installed.

And, you were able to re-format the drive without a problem? Because this sounds like a malfunctioning drive unless you aren't actually booted from the Recovery HD or are trying to reinstall Snow Leopard.

What is the computer's model ID? To find the model identifier open System Profiler in the Utilities folder. It's displayed in the panel on the right.

Not being sure if the HDD is good or bad, I suggest you first make a backup of your files. Then do the following:

Clean Install of Snow Leopard

Be sure to make a backup first because the following procedure will erase

the drive and everything on it.

     1. Boot the computer using the Snow Leopard Installer Disc or the Disc 1 that came

         with your computer.  Insert the disc into the optical drive and restart the computer.

         After the chime press and hold down the  "C" key.  Release the key when you see

         a small spinning gear appear below the dark gray Apple logo.

     2. After the installer loads select your language and click on the Continue

         button. When the menu bar appears select Disk Utility from the Utilities menu.

         After DU loads select the hard drive entry from the left side list (mfgr.'s ID and drive

         size.)  Click on the Partition tab in the DU main window.  Set the number of

         partitions to one (1) from the Partitions drop down menu, click on Options button

         and select GUID, click on OK, then set the format type to MacOS Extended

         (Journaled, if supported), then click on the Apply button.

     3. When the formatting has completed quit DU and return to the installer.  Proceed

         with the OS X installation and follow the directions included with the installer.

     4. When the installation has completed your computer will Restart into the Setup

         Assistant. After you finish Setup Assistant will complete the installation after which

         you will be running a fresh install of OS X.  You can now begin the update process

         by opening Software Update and installing all recommended updates to bring your

         installation current.

     5. If you are planning to sell or give your computer away, then do the following:

        After you reformat your hard drive and reinstall OS X, the computer restarts to a

        Welcome screen and asks you to choose a country or region. If you want to leave

        the Mac in an out-of-box state, don't continue with the setup of your system. Instead,

        press Command-Q to shut down the Mac. When the new owner turns on the Mac,

        the Setup Assistant will guide them through the setup process.

Download and install Mac OS X 10.6.8 Update Combo v1.1. At this point you can proceed further if you wish:

Upgrading to Yosemite

You can upgrade to Yosemite from Lion or directly from Snow Leopard. Yosemite can be downloaded from the Mac App Store for FREE.

Upgrading to Yosemite

To upgrade to Yosemite you must have Snow Leopard 10.6.8 or Lion installed. Download Yosemite from the App Store. Sign in using your Apple ID. Yosemite is free. The file is quite large, over 5 GBs, so allow some time to download. It would be preferable to use Ethernet because it is nearly four times faster than wireless.

    OS X Mavericks/Yosemite- System Requirements

      Macs that can be upgraded to OS X Yosemite

         1. iMac (Mid 2007 or newer) - Model Identifier 7,1 or later

         2. MacBook (Late 2008 Aluminum, or Early 2009 or newer) - Model Identifier 5,1 or later

         3. MacBook Pro (Mid/Late 2007 or newer) - Model Identifier 3,1 or later

         4. MacBook Air (Late 2008 or newer) - Model Identifier 2,1 or later

         5. Mac mini (Early 2009 or newer) - Model Identifier 3,1 or later

         6. Mac Pro (Early 2008 or newer) - Model Identifier 3,1 or later

         7. Xserve (Early 2009) - Model Identifier 3,1 or later

To find the model identifier open System Profiler in the Utilities folder. It's displayed in the panel on the right.

     Are my applications compatible?

         See App Compatibility Table - RoaringApps.

Upgrading to Lion

If your computer does not meet the requirements to install Mavericks, it may still meet the requirements to install Lion.

You can purchase Lion at the Online Apple Store. The cost is $19.99 (as it was before) plus tax.  It's a download. You will get an email containing a redemption code that you then use at the Mac App Store to download Lion. Save a copy of that installer to your Downloads folder because the installer deletes itself at the end of the installation.

     Lion System Requirements

       1. Mac computer with an Intel Core 2 Duo, Core i3, Core i5, Core i7,

           or Xeon processor

       2. 2GB of memory

       3. OS X v10.6.6 or later (v10.6.8 recommended)

       4. 7GB of available space

       5. Some features require an Apple ID; terms apply.

Use the installer disc that came with the computer. It doesn't have to be Snow Leopard until you try upgrading beyond Snow Leopard. You can get a Snow Leopard disc through the Apple Store: Mac OS X 10.6 Snow Leopard - Apple Store (U.S.). The price is $19.99 plus tax. You will be sent physical media by mail after placing your order.