Carel distributors can order a pre-configured USB stick with diagnostics and programming tools. This is not free, but it is the only officially supported "portable" solution.
Install the software normally on your office PC. After installation, navigate to the installation folder (usually C:\Program Files (x86)\Carel\c.suite). carel pco programming software download portable
For older controllers, PCO Manager is less complex. Some technician communities have compressed the entire PCO Manager folder from C:\Program Files into a ZIP file. Extracting this to any PC and running PCOMan.exe occasionally works, provided the PC has the correct MSVBVM50.DLL (Visual Basic runtime) files. Carel distributors can order a pre-configured USB stick
You cannot update firmware without the full IDE runtime. However, you can copy the firmware .bin file to your portable drive and run the IDE from there. Install the software normally on your office PC