OT: File compression on CDRom

[karina.popkova at verizon.net (karina.popkova at verizon.net)]

Good Morning,

My mother has a CDRom with some Medical Questions
(Self Study material), that has a number of files on it.
The files have file extensions such as:
.DL_
.DE_
.LE_
.EX_
.TL_
.LST
.ME_ 
etc.

My Google shows these to be compressed files
put onto the CDRom. 

The underscore (.DL_) will be removed
upon decompression and an appropriate letter
substituted (perhaps .DLL, or something else).

There is a setup routine (?) that indicates
"setup bootstrap for Visual Basic" via a tooltip.

clicking on this Icon reveals an error:
"Setup fatal error, unable to generate
installation log file".

Obviously, clicking on any other of the 100's
of files produces NO change ...

Any suggestions on how to decompress these files
or how to salvage the 100's of files on this
CDRom?

TIA

karina