You didn't mention that you copied the hdr file to that folder as well - but I assume you did.
As it is Securom 4.8, it is a new game, and a lot of new games now have a new algorithm or whatever for the installation cabinet files - it's been updated. I don't think that this version of i6comp will handle the files you have.

Okay, last chance:

There a three reasons why this error message comes up:
(maybe there are more, but not for me at the moment :D)

1) data1.hdr cannot be found --> must be in the same folder
2) data1.hdr is write protected
3) i6comp version ist not compatible with this version of installshied (unlikely, cos i6comp then quits with an appropriate message).

oh well what a shame so close and yet so far !!!
typical my 1st attempt squashed!!!!thanks anyway perhaps a newer version of icomp may materialise eventually ?

monty why is it named data1.hdr?
when Im calling it data1.cab??
it is in the folder with the fixed exe and icomp its name from the folder is data1 a win rararchive compressed file at 289,205kb

Well, it's your time and all, but I would never have even tried doing that. What's the use ? When the next official patch gets out, you'll still need to copy the original executable after each install in order to be able to patch. Plus there seems to be about a thousand things that can go wrong if you mess with installers and cabs :D

the properties show it as not write protected in attributes there is no tick in hidden or read only could it be a locked file of somesort?

@ Rince
Right, of course, but if somebody wants to do it to learn from it, why not.

@logicwatch
I am still confused. When there is a data1.cab then there should also be a data1.hdr or it is a new version where hdr file isn't needed anymore

if i explore the disc there is no folder or icon called data1.hdr
only data1 the compressed /zipped archive . heres a list of the disc contents......
autorun
autorun setup info
jpog icon
jurassic park operation genesis installer package
setup
direct x
data1
splash bitmap
should ther be another folder called data1.hdr?if so where does it hide and is it hidden???
thanks in advance

It may be hidden as you suggest - so in Windows Explorer goto Tools then Folder Options - then goto the View tab and make sure Show Hidden Files and Folders is selected.