After a hard dive crash - HELP!

Question

Please Help!
A month ago, I got the dreaded blue screen of death. I was an idiot (I'll say it) and didn't back up any of my music. I contacted Apple and they were kind enough to give me one time grace to re-download all my lost purchased music, which I did. About 800 songs later, I unfortunately was not able to download an additional 200 or so songs that were no longer on iTunes or just didn't download properly.
My friends was able to go into my old hard drive and copy most, if not all, of my music onto DVDs. The songs that did not re-download are on there (protected files). When I got my computer up and running again (new hard drive, new iTunes AND a back up drive now) I went to drag and drop my previously imported/purchased music into the iTunes library....
Here's the problem: most, if not all, of the music on these four DVDs did not copy over into my new iTunes library. I registered the new iTunes and authorized it to play on my computer, but still, whenever I drag and drop a Protected purchased file onto the library, it fails to read and/or copy the file over to my library...hence, not play.
I have tried different variations to get the music back on: drag and drop, file import, folder import, File: Add, copying the whole folder onto my desktop THEN trying to add it... NOTHING WORKS.
I purchased these songs and now they seem to be locked forever on my DVDs, unable to import and play on my new REGISTERED iTunes, under the same account and name.
Can you please help me with any thoughts or suggestions that I may be missing?
Thanks!

Answer 1

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.)