Thank you for the code Dmit.

But the code like you posted it here doesn't correctly work for me and perhaps for others neither. I compiled it with VC++ ("ISDHelper.exe") and tried it with some encrypted SETUP.INX files.

I tried the following commands:

"ISDHelper < SETUP.INX > NewSETUP.INX"
and
"Type SETUP.INX | ISDHelper > NewSetup.INX"

But both commands truncated the output file at different locations and didn't fully decrypt it. The same result with DMC. Then I used BC++ to compile (I had to rename "_setmode" to "setmode" and it worked fine.

What could be the reason for this?