Why does CD-ROM not work after adding a hard drive?

If a CD-ROM (compact disc read-only memory) program or game fails to work after installing a new hard disk drive, reinstall the program to reinitialize any files that point to the old drive letter.

Some programs have settings and files on the computer that rely off a drive letter used when they were first installed. When a new drive is installed the CD-ROM, the drive letter changes to that of the previous drive, and breaks these programs.