During the install process of modern versions of Jet Reports, the install program queries the Windows Registry to determine the "bit level" of Microsoft Office.
The install program will first examine this Registry key
to determine what version of MS Office is installed.
If you are using a 64-bit version of Windows and the version of Office could be either a 32-bit or 64-bit edition, the Jet install program will then query the Registry to find out which edition is present.
Microsoft Office stores this information in this Registry key:
If that Registry key is not present, the Jet install program will not be able to verify the edition of MS Office and the install will stop.
If that Registry key setting (either "x86" or "x64") is somehow configured for an incorrect value (including case sensitivity), the install will proceed, but Excel will not be able to enable the Jet add-in because the bit level of the two applications will not match.
If there is an issue with the Windows Registry that is preventing you from installing Jet Reports or is preventing Jet Reports from working once it is installed, please contact your system administrator for the best solution for your organization.