>You have to place it where the original .exe is do run thegame.
>
>Find it and replace it. Just save it first.

If the program did not install at all because the drive cannot read
the DVD, having a replacement exe will not help at all.

You need to test the DVD in another drive/computer to check that they
are not defective. If they read fine then you need a replacement
drive. Unless the DVD runs and install but from what you say the drive
cannot read them at all?

===
All the best!
Katy Pluta