Whenever I try to open my itunes, I get a box that says, "Apple Application Support was not found. Apple Application Support is required to run itunes. Please uninstall itunes, and then reinstall it. Error 2 (windows error 2)."?

Your uninstalling then reinstalling the application, not your music library. You are asking to do this because something is corrupted or missing. This is the best and fastest way to fix the problem.

Let's try a standalone Apple Application Support install. It still might not install, but fingers crossed any error messages will give us a better idea of the underlying cause of the issue.

Download and save a copy of the iTunesSetup.exe (or iTunes64setup.exe) installer file to your hard drive:

http://www.apple.com/itunes/download/

Download and install the free trial version of WinRAR:

http://www.rarlab.com/

Right-click the iTunesSetup.exe (or iTunes64Setup.exe), and select "Extract to iTunesSetup" (or "Extract to iTunes64Setup"). WinRAR will expand the contents of the file into a folder called "iTunesSetup" (or "iTunes64Setup").

Go into the folder and doubleclick the AppleApplicationSupport.msi to do a standalone AAS install.

Does it install properly for you? If so, does iTunes launch properly now?

If instead you get an error message during the install, let us know what it says. (Precise text, please.)