ISO upgrade images that are downloaded from Cisco's download repository can theoretically be made bootable.
Please note that the following post, describing the steps to make a bootable ISO, is not supported by Cisco and should not be used in a production environment.
OK, now we got that out of the way, let me explain. The ONLY difference between a bootable disc and a non bootable disc that you would obtain from Cisco's CCO, is the boot sector. Why Cisco doesn't make all disks bootable, is beyond me. For example you can obtain a bootable disc with UCCX version 8.5.11000 and you can download UCCX 8.5.11004, which is bootable. So to bring 8.5.1100 to 8.5.11004 you would have to perform an upgrade. If you would have a bootable ISO of version 8.5.11004, you could do a fresh installl of this version, rather then going through the two stepped process.
There is really not much to making a disc bootable.
- Extract the boot sector from an existing bootable disk:
Save the boot file to your hard drive, name is not important (could be boot.bif , start.bif).
You can keep the same file for future use, making other bootable disks/ISO's
2.Adding the boot file to a non-bootable disc.
Open the non-bootable image in UltraISO. Go to menu "Bootable". Make sure "Generate Bootinfotable" was checked. Then choose "Load Boot File...".
Now choose the boot file that was saved in step 1 (boot.inf or start.inf)
The image type should now have changed to "bootable"
Now finish with: "File > Save As" to save the bootable image to an ISO file.
and last but not least: