Problem installing Starcraft 2?

OK, so I bought my dad the game and when we tried to install from the disk, at 51% it stops and gives an error code saying that it cannot read a file, and that your disk may be damaged, dirty, or the disk drive might be damaged.

Looks something like "fileset.base\Mods\Core.SC2Mod\Index.SC2Locale" for the file it cannot read, but it sometimes it's different exact file with similar wording.

A) I know the disk drive is fine because the DVD/RW drive itself had been replaced a year ago and and he was just playing another game fine that needs the disk to play a day ago

B) We returned the disk to the store for another one and it still stops at 51% with another error of similar type but says it cannot read a certain fiel, the file names are always different but similar looking.

I tried to install in Safe Mode

I have made sure all hidden files are shown, and it is run as an administrator

- I tried to copy all the files from the the DVD drive folder to a folder on the desktop and it stops halfway through and says it cannot read a file to copy it.

Now I know the disk is not damaged because why would two seperate disks have the same error on the same exact part of installation????

What is going on here?

He has a Vista 32-bit OS, His specs are fine (although we plan to add memory chips if the gameplay is slower than he wants)

If anybody has words of wisdom I'd be extremely happy.